<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta>
      <issn pub-type="ppub">1613-0073</issn>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>environments for Mixed Initiative Artificial Intelligence as a method for prototyping video game levels</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Sokol Murturi</string-name>
          <email>sokol.murturi@falmouth.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Joseph Walton-Rivers</string-name>
          <email>Joseph.Walton-rivers@falmouth.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Michael James Scott</string-name>
          <email>michael.scott@falmouth.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Falmouth University, Faculty of Screen, Technology and Performance</institution>
          ,
          <addr-line>Cornwall</addr-line>
          ,
          <country country="UK">United Kingdom</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Goldsmiths University of London, Department of Computing</institution>
          ,
          <addr-line>London</addr-line>
          ,
          <country country="UK">United Kingdom</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2025</year>
      </pub-date>
      <fpage>9</fpage>
      <lpage>13</lpage>
      <abstract>
        <p>Recent advancements in artificial intelligence and human-computer interaction have led to tools that help human authors collaborate creatively with computing systems. Many such tools are available for 2D video games, but exploration of these techniques in a 3D environment is necessary. This paper introduces Melete, a mixed-initiative artificial intelligence tool which uses the Wave Function Collapse algorithm and a human-in-the-loop design process to create and test 3D levels and environments for video games. Analysis by a panel of expert game developers in two design challenges-a battle royale game and a real-time strategy game-indicate that Melete enhances designer engagement and facilitates iterative design. However, it also draws attention to the importance of play testing in the design loop, kernel generation and the usability of such tools. The findings suggest that Melete's workflow helped designers to seed ideas, explore concepts, and refine implementations quickly with creative agency, but also suggest that further work is needed to integrate Mixed-Initiative Artificial Intelligence techniques into design tools efectively.</p>
      </abstract>
      <kwd-group>
        <kwd>tive</kwd>
        <kwd>game</kwd>
        <kwd>game design</kwd>
        <kwd>levels</kwd>
        <kwd>environments</kwd>
        <kwd>development tool</kwd>
        <kwd>computational creativity</kwd>
        <kwd>expert evaluation</kwd>
        <kwd>qualita-</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        AI.[
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]
CEUR
      </p>
      <p>ceur-ws.org
pipelines discussed in this paper focus primarily on level development for 2D games, such as Mario,
The Legend of Zelda, and physics-based puzzles, such as Cut the Rope. Although these games have a
strong presence in academic research, applying state-of-the-art MIAI techniques to an industry settings
requires systems that support level design and prototyping for 3D environments.</p>
      <p>
        Developing levels in 3D which is commonly reserved for AAA studios[
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] presents several challenges,
one of the most significant being play testing. Play testing is a crucial part of the game development
cycle and is increasingly recognized as standard practice. It is widely employed in Games User Research
(GUR) to enhance usability, player experience, and the development life cycle itself[
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]. GUR, an
interdisciplinary field rooted in psychology and Human-Computer Interaction (HCI), enables developers
to refine designs through designer evaluations that provide deeper insights into possible player behavior
and interaction.
      </p>
      <p>However, many MIAI pipelines focus primarily on level generation without integrating play testing
mechanisms, limiting their potential to support comprehensive game development workflows,
particularly for complex 3D environments. To allow developers to create meaningful applications of MIAI
pipelines it is crucial to establish and ensure their efectiveness as tools for creative endeavors.</p>
      <p>The primary contributions of this paper are:
• The introduction of a novel MIAI pipeline, Melete. That can be used for prototyping map layouts
for 3D environments.
• Data analysis of an expert review, that highlights the importance of play test integration of MIAI
pipelines.</p>
      <p>In this paper, we explore existing MIAI pipelines and their limitations, with a particular focus on
their application in game design. We provide a range of recent examples to showcase the diverse
applications of MIAI Pipelines. Following this, we present our approach to validating our own MIAI
system, Melete, along with an in-depth look at its 3D designer-in-the-loop creative process. This
includes an overview of the Wave Function Collapse (WFC) algorithm, emphasizing its texture synthesis
approach for kernel generation. We then present our expert analysis and qualitative validation approach
for Melete, highlighting the critical role of play testing in MIAI pipelines. The paper concludes with
recommendations for future research and potential improvements to MIAI pipelines.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Background</title>
      <sec id="sec-2-1">
        <title>2.1. Procedural content generation</title>
        <p>PCG has emerged as a highly active research field over the past two decades, focusing on the generation
of game levels, environments, and other virtual content. Originally rooted in academia, PCG is now
widely used across the gaming industry, with popular titles like Valheim, Dwarf Fortress, Diablo 4,
and Starfield relying on it for level generation. Beyond level design, PCG systems have expanded to
generate text, stories, textures, and even entire games.</p>
        <p>
          Despite its widespread adoption, the field still lacks standardized evaluation frameworks for assessing
the quality and efectiveness of new PCG approaches[
          <xref ref-type="bibr" rid="ref11 ref12 ref13 ref3">11, 12, 13, 14, 3</xref>
          ] In Withington et al. [15] the
authors address this challenge by developing a novel taxonomy of PCG evaluation methods and
conducting a survey of recent research, analyzing current practices through this framework.
        </p>
        <p>The authors identify a key limitation in their analysis: the treatment of Mixed-Initiative PCG systems,
where human designers collaborate with AI during content creation. While they include an “Evaluated
through Mixed-Initiative Creation” category, this classification is limited to evaluations involving
human-in-the-loop interactions, where user data is collected either during or after the level design
process. This gap underscores the need for more refined evaluation approaches tailored to the unique
challenges of Mixed-Initiative systems and how PCG systems also not be evaluated in the same way as
PCG systems.</p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Human Computer Interaction</title>
        <p>HCI examines how users interact with software, hardware, and digital interfaces, aiming to create
systems that align with human capabilities and needs. MIAI systems aim to integrate artificial intelligence
into these frameworks. Shneiderman et al. [16] introduced a framework to aid in the development
of digital interactive tools for creative problem-solving, a well-established area in creativity research
(e.g.[17, 18]). In exploring the potential to enhance individual creativity through new tools, Shneiderman
et al. [16] considered both widely used general-purpose and other design tools like text editors and
spreadsheets and other specialized applications in architecture, graphic design, and engineering.</p>
        <p>Before integrating AI into design tools, the need to research user interaction with Creativity Support
Tools (CSTs) was already identified by the HCI community [ 19]. In his call for researchers to explore
future developments in CSTs, Shneiderman et al. [19] also emphasized the evolving nature of tool
evaluation and the importance such evaluation plays in establishing the value of CSTs to end users.
The development of MIAI pipelines brings to the front the need to identify HCI and PCG methods of
validation.</p>
        <p>
          HCI researchers have implemented a broad spectrum of methodological approaches to validating
pipelines. Quantitative methods mainly focus on analysing the outputs of systems or conducting
surveys[
          <xref ref-type="bibr" rid="ref4">4</xref>
          ]. These quantitative approaches allow for the rapid testing of multiple systems in a relatively
short period of time. In contrast, qualitative methods can provide insights into the users’ thought
processes and provide nuanced information about how the user perceives the CST. The deployed
techniques include structured interviews, speak-aloud interviews, expert interviews and grounded
theory[20].
        </p>
        <p>
          With this in mind, it is important to note that the design of MIAI pipelines and their features is
a generative process, with incremental contributions being added over time by many academics, for
example, the use of level culling methods being integrated into MIAI pipelines[
          <xref ref-type="bibr" rid="ref4">4, 20, 21</xref>
          ] to help inform
designers about the structural issues of the artifacts they are designing during their interaction with
the MIAI pipeline, although this trend is not observed, or systematically analyzed through quantitative
measures. These insights provided by experts align closely to research through design(RtD)[22], where
the foucs of scholars is argued by authours such as Zimmerman et al. [23] and Stolterman et al. [24]
should be making the “right thing” to advance research in the “right” direction.
        </p>
      </sec>
      <sec id="sec-2-3">
        <title>2.3. Mixed-Initiative Artificial Intelligence</title>
        <p>One of the many challenges that MIAI researchers face, is that of where and how does AI fit into
complicated and creative processes. In Margarido et al. [25] the authors address the challenges in
human-computer collaboration during game design, particularly focusing on the communication gap
between human designers and computational agents. Some considerations for MIAI pipelines as a
whole claimed that the role of AI in human-AI collaboration relies on the capability of AI [26] (i.e., AI as
a teammate when AI performance is better than human performance and AI as external stimuli when
AI performance is worse than human performance). In Melete, these considerations have been made
using the Wave Function Collapse (WFC) algorithm, which allows designers to give Melete, the MIAI
pipeline/agent in this case a simple design that can be rapidly iterated on by the agent to present possible
designs to the authour which they may like. While the roles of AI emphasize the positive impact of AI
in human-AI collaboration, Pandya et al. and Zhang et al. [27, 28] showed that human-AI collaboration
can produce better outcomes when the AI contributes a better performance than the human. If the AI
performs at the same level or worse than a human, it is likely to lead to less favorable results. While
MIAI pipelines ofer significant benefits for rapidly prototyping and tackling complex tasks, novice
users are more prone to making mistakes. This underscores the need for experts to thoroughly evaluate
MIAI pipelines before they are introduced or exploring concepts with novice users.</p>
        <p>Some recent studies investigated the role of AI and the impact of AI on ideation in human-AI
collaboration. Liao et al. [29] presented three potential roles of AI-based inspirations in ideation that
are closely related to the interaction paradigm providing suggestions described in the following:
• AI as representation creation (providing inspirations by suggesting texts or images)
• AI as an empathy trigger (supporting the designer’s descriptive thinking)
• AI as engagement (helping the designer avoid fossilization[In this context fossilization refers to
the learning and repeated implementation of incorrect habits when it comes to writing/design]
and perform typical design actions)</p>
        <p>A short Taxonomy of MIAI systems was presented by Lai. et al[30] in which they present some of
the previous works of MIAI systems and identify some of the core areas of interest for MIAI pipelines
which included: 2D Images, 2D models, 3D Assets, Animation, Code, Dialogue, Game Design, and
Level design. Melete as an MIAI pipeline focuses on level design, thus, we will focus on these types of
MIAI pipelines. An example of the diference between game design and level design is ”Evaluation of a
Recommender System for Assisting Novice Game Designers,”[31] in which the authors introduce an
AI-driven game design assistant that suggests game mechanics, whereas examples such as Sentient
Sketchbook[20] focus on topology aspects of levels.</p>
        <sec id="sec-2-3-1">
          <title>2.3.1. Testing MIAI in Game Development and the role of playtesting</title>
          <p>
            The majority of game development tools such as Unity, Unreal, Godot, Scratch, etc., include
playtesting functionality built into their design and as stated earlier play testing is an essential component in
GUR[
            <xref ref-type="bibr" rid="ref10">10</xref>
            ]. In this sub-section we will present other MIAI system papers and explore their implementation
and whether they have a playtesting functionality, in addition to how they were tested.
          </p>
          <p>One of the most prevalent and arguably one of the keystone papers of MIAI systems, the Sentient
Sketchbook[20] is a tool designed to assist game designers in creating levels. It simplifies the design
process by using map sketches while automating playability checks, evaluations, and visualizations
of key game play properties. Although the Sentient Sketchbook is the only other system that in later
versions has a 3D visualization component, it does not have a method for testing the output of the
interaction beyond visual inspection. That being said, it was one of the first academic explorations
of MIAI pipelines for level design. To test the usability of Sentient Sketchbooks, a small-scale expert
analysis was conducted.</p>
          <p>Another example of MIAI in game design is 3Buddy[32], which is an MIAI tool designed to function
as a digital peer, ofering creative stimuli during level design rather than merely executing commands.
It generates content using the Legend of Grimrock 2 level editor, which is a 2D top-down editor
without playtesting integration. In order to analyze the HCI aspects of the tool, a user study was
conducted, involving six participants who completed a four-question Likert scale questionnaire. While
three participants were experts and the results were promising, the small sample size limits statistical
inference. Additionally, the use of a Likert scale may have led to a loss of nuanced data, afecting
the depth of insights gained from the expert participants. Papers such as Liapis et al.[33] make
recommendations for questions that could be put towards asking qualitative research in MIAI pipelines.
As an approach to validating the usability of MIAI pipelines both these approaches show promise;
however, in our research we have opted for a qualitative approach.</p>
          <p>Automated play testing in MIAI Automated playtesting presents two interesting areas of possible
research in MIAI systems; the importance of providing information to the designer, and a possible
avenue for allowing MIAI systems to directly interact with the designers actions.</p>
          <p>
            One approach to validating the usability of MIAI pipelines has been to use automated playtesting
to ensure that the quality of the levels that are being produced can be used in a video game context.
Roposseum[
            <xref ref-type="bibr" rid="ref4">4</xref>
            ]is an example of how physics-based puzzle solvers can help ensure designers create
playable puzzles for the cut the rope game, which is a 2D puzzle game for mobile phones.
          </p>
          <p>Other examples of automated playtesting include MIAI systems such as Tanagra[34] used to design
2D platformers and has the unique ability to override the designers input to ensure level playability. In
”Integrating Automated Play in Level Co-Creation”[21], the authors enhance the Morai Maker[35], a
mixed-initiative level editor for Super Mario Bros, by integrating automated pathing and introducing
an A* reachability check to ensure level traversal. This is a similar approach to how the Sentient
Sketchbook approached resource placement and in both examples an A*-based analysis to approximate
dificulty/fairness was used.</p>
          <p>
            Another example of automated playtesting is presented in the paper ”Toward Co-Creative Dungeon
Generation via Transfer Learning”[36]. The authors present another possible avenue for research with
automated playtesting, where they address the challenge of acquiring co-creative training data necessary
for Procedural Content Generation via Machine Learning (PCGML) systems, to efectively collaborate
with human designers. The authors address this via helping users design levels for both Mario and
Zelda style 2D games. To overcome the dificulty and time consumption associated with collecting
such data, they propose approximating human-AI interaction data and employing transfer learning
techniques. Examples of this can be found in ”Mixed-Initiative Level Design with RL Brush”[
            <xref ref-type="bibr" rid="ref14">37</xref>
            ], where
the authors introduce RL Brush, a level-editing tool for tile-based games that facilitates mixed-initiative
co-creation by integrating reinforcement learning (RL) models to provide AI-generated suggestions
during human level design. The tool is applied to the classic puzzle game Sokoban, a 2D Zelda style
game allowing users to manually design levels while receiving AI-driven recommendations to enhance
playability and complexity. This approach involves adapting co-creative knowledge learned from one
game to facilitate dungeon room generation in another game, specifically focusing on co-creative Zelda
dungeon room generation. To validate their MIAI tool automated playtesting to assess the quality of
output which restricts the designer from playtesting the environment in the tool they are using to
design with. Automated playtesting for information presentation is one area that we have currently
not explored with Melete. However its’ use in the academic space presents an interesting avenue for
further research.
          </p>
        </sec>
        <sec id="sec-2-3-2">
          <title>2.3.2. Large Language Models</title>
          <p>
            The papers ”Level Generation through Large Language Models” [
            <xref ref-type="bibr" rid="ref15">38</xref>
            ] and ”Consistent Game Content
Creation via Function Calling for Large Language Models” [
            <xref ref-type="bibr" rid="ref16">39</xref>
            ] explore the integration of Large Language
Models (LLMs) into what can be considered MIAI pipelines for game development. Both systems
generate 2D levels, with one focused on Sokoban puzzles and the other on top-down dungeon layouts.
However, neither system incorporates a playtesting mechanism, meaning users cannot directly test
the environments they design within these frameworks. While this remains an under-explored area in
MIAI research, the use of LLMs presents a novel approach to content generation by enabling designers
to input text-based ideas, which AI then translates into potential level topologies to support the design
process.
          </p>
          <p>
            Play testing included Anhinga[
            <xref ref-type="bibr" rid="ref17">40</xref>
            ], presents a unique approach to play testing, where users can play
a selection of levels from the original Snakebird (a 2D Game) and request the Exhaustive Procedural
Content Generation (EPCG) system to suggest the single best modification to the current level based on
an evaluation function. While the system qualifies as mixed-initiative PCG, the authors note that it
is not yet fully co-creative due to limitations in human-AI interaction. Whereas Lode Enhancer[
            <xref ref-type="bibr" rid="ref18">41</xref>
            ]
and Kumaran et al.[
            <xref ref-type="bibr" rid="ref19">42</xref>
            ] present approaches to playtesting 2D games after the interaction process are
completed. Germinate[
            <xref ref-type="bibr" rid="ref20">43</xref>
            ] is an example of playtesting of 2D games during the design process.
          </p>
          <p>Many of the limitations presented by the paper mentioned above have been addressed by Melete.
The key areas in which Melete diferentiates itself are:
• 3D and 2D level creation
• Interaction loop
• Playtesting</p>
          <p>Many of the systems discussed in this section have primarily focused on 2D level creation, limiting
their applicability to more complex spatial design tasks. While Melete does support 2D level generation,
this version extends beyond those constraints by leveraging MIAI for 3D level creation—an area that
has received comparatively less attention. Additionally, prior systems often ofer limited, ”black-box”
interactions, where users are presented with opaque suggestions from the agent. In contrast, Melete
emphasizes transparency and user agency: users actively guide the system by interacting with the Kernel
and selecting from the agent’s outputs, fostering a more collaborative design process. Moreover, many
previous approaches neglect the iterative nature of real-world game development, which heavily relies on
continuous playtesting and refinement. Melete is explicitly designed to support this iterative workflow,
aligning with the practices emphasized in GUR and contemporary game development environments.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Melete</title>
      <p>This section outlines the implementation of Melete, which consists of three key stages of user interaction.
In the first stage, data entry, the user engages with the WFC algorithm by designing a kernel to train it,
described in section 3.1. Next, the user enters an interactive loop with the algorithm’s output, where
they can refine the design, adjust elements, load assets in real time, and playtest their work. In the final
stage, the user can save the completed design. Figure 1 illustrates Melete’s overall structure.</p>
      <sec id="sec-3-1">
        <title>3.0.1. Data Entry</title>
        <p>When the designer begins using Melete, they are presented with an empty ”Canvas,” which functions
as the data input section for the WFC algorithm. Through this user interface, the designer can populate
the canvas with gameplay semantics.</p>
        <p>To populate the canvas with game-play semantics, the user interacts with the canvas within the
Unity editor and a predetermined palette is used to fill the Canvas.</p>
        <p>Melete’s implementation of WFC is distinct from other examples of the algorithm. In most cases,
WFC represents concrete data, with each tile corresponding to a specific component of an artifact.
In contrast, Melete abstracts this information, using colors to represent data instead. This approach
allows gameplay semantics to be embedded directly into the data representation. Although users are
not required to understand the theoretical foundations of the WFC algorithm, it will help the user
manipulate the output of the algorithm. Despite this, the flexibility of Melete makes it an efective
example of an MIAI pipeline for rapid content development, enabling users to engage with it from a
genre-agnostic perspective. Its abstract representations are highly versatile, applying to both 2D and 3D
games, and can incorporate gameplay behavior scripts, such as arrays of 3D models programmatically
instantiated during the interaction cycle.</p>
        <p>In the current iteration of Melete, the gameplay semantics are constructed ofline, which means
users cannot edit the underlying data representations during run-time. The data present in the palette
represents:</p>
        <p>• Orange: Areas outside of buildings.</p>
        <p>Once the user completes their initial design, this information is sent to the WFC algorithm for
analysis. An interesting feature of Melete is its ability to recognize special-case scenarios and place
objects accordingly. This leverages the WFC algorithm’s feature-preserving behavior from the training
data. Designers can use this to create specific structures, like staircases, by encoding these features
in the training data. For instance, a combination of cyan, grey, and teal can signify where a staircase
should appear. In figure 3, the system identifies this special-case scenario and places a staircase in the
environment.</p>
        <p>This palette is derived from the palette used in the data entry stage of Melete. Since the palette data
is independent of the WFC algorithm, this allows for a genera-agnostic approach to PCG and game
design, allowing the user to represent not only 2D and 3D environments but also depending on the
user’s needs diferent genres of games, for example, top-down Legend of Zelda style 2D games or in
this case a third person battle royal style environment.</p>
        <sec id="sec-3-1-1">
          <title>3.1. Wave Function Collapse</title>
          <p>
            The WFC algorithm is a constraint-solving technique that uses user-defined generative grammar to
generate images. Originally implemented Maxim Gumin, described in[
            <xref ref-type="bibr" rid="ref21">44</xref>
            ] WFC is inspired by the
quantum mechanical WFC formula, as presented by Schrödinger and further explored in Max Born’s
research on quantum mechanical systems [
            <xref ref-type="bibr" rid="ref22">45</xref>
            ]. However, as far as the implementation of WFC in
computing the algorithm itself servers as a constraint solving algorithm [
            <xref ref-type="bibr" rid="ref23">46</xref>
            ].
          </p>
          <p>The algorithm requires an input image provided by the user before the preprocessing phase. Which
in the case of Melete is the data input portion It then analyzes this image and generates similar outputs
based on the input data. figure 5 illustrates this process, showing three input images on the left, their
corresponding example outputs on the right, and the constraint-solving process in between.</p>
          <p>The use of WFC for programmatically generating content can be divided into two distinct phases.
The first is the pre-processing phase, where an image provided by the user is analyzed and interpreted
into data that the algorithm can use to generate content. The second is the generation phase, where the
extracted information is used to create new images similar to the input.</p>
          <p>During the pre-processing phase, the input image is divided into small square sections, typically
using a value of two for the square size. These sections are then used to create tiles, which are groups
of pixels representing small portions of structural information from the input image. These tiles are
cataloged, weighted, and assigned rules, forming the foundation for content generation in the next
phase.</p>
          <p>To create tiles, the WFC algorithm compares all possible square sections of the input image based on
their pixel information. Each tile is assigned a name derived from its pixel composition, and squares are
rotated to account for all possible rotational transformations. These transformations are added to the
catalogue regardless of whether they appear in the original input image. Once all tiles have been named
and catalogued, duplicate tiles with identical pixel information are removed from the catalogue and
instead assigned weighted values, increasing the likelihood of their occurrence in the generated output.</p>
          <p>After defining all possible tiles from the original image, the algorithm assigns rules that determine
how tiles can connect to one another. To verify connectivity, the WFC algorithm overlaps each tile
with every other tile in the catalogue, assessing compatibility based on the number of possible ofsets
for that tile.((2( − 1) + 1) 2) − 1.</p>
          <p>If the pixel values match in the overlapping areas, a placement rule is established for that tile. Once
all necessary information about the input image has been gathered, the WFC algorithm moves on to the
generation phase. This phase begins by selecting a random point within the output grid and placing a
randomly chosen tile from the catalogue at that position. Once the initial tile is placed, the algorithm
starts filling in the rest of the output.</p>
          <p>To track which tiles need to be placed and which have been resolved, the WFC algorithm stores
coordinate positions in a Boolean array. As tiles are placed, their corresponding Boolean values switch
from true to false. This process helps the algorithm monitor the outer edge of the solution while also
identifying tiles that have been fully surrounded by correctly placed neighbors. The algorithm then
focuses on solving the remaining grid by analyzing tiles that have been placed and have at least one
neighboring true value. This approach ensures that the algorithm identifies the tile with the lowest
number of possible solutions.</p>
          <p>To determine the tile with the fewest placement options, the WFC algorithm checks each tile’s rule
index and compares it to the values of surrounding tiles. With each tile placement, the algorithm both
solves that tile and reduces the number of acceptable rules for adjacent tiles.</p>
          <p>In rare cases where an unsolvable position arises, local backtracking can be applied. The algorithm
identifies problematic tiles with neighboring true values and refers to the Boolean array to remove all
false values adjacent to a true value. This backtracking process allows the WFC algorithm to adjust the
solution and continue resolving the output. The algorithm terminates once no further valid placements
remain.</p>
          <p>WFC is influenced by the computer graphics technique known as texture synthesis. While texture
synthesis methods are typically used to repair and correct digital images, WFC difers in that it does
not merge or average adjacent pixels. This distinction allows it to be a useful component of an MIAI
system such as Melete as it preserve gameplay semantics embedded within the training image.</p>
          <p>The WFC algorithm takes a probabilistic approach to procedural content generation (PCG). While
other probabilistic PCG methods exist, they difer from WFC in their implementation. Traditional
systems rely on programmatically defined generative grammar, whereas WFC enables users to visually
create a representation of generative grammar. This grammar is influenced by both spatial relationships
and the probabilistic proximity of other rules within the input data, following the principles of the
Wave Function Collapse formula.</p>
        </sec>
      </sec>
      <sec id="sec-3-2">
        <title>3.1.1. Data Input and preprocessing</title>
        <p>Before the WFC algorithm can generate output images, it requires user-provided data. During the data
input stage, the user interacts with a blank canvas and a palette. The palette contains game objects,
which serve as templates in Unity and are used by the algorithm to construct the final output.</p>
        <p>In the example presented in figure 2, The palette below the data entry section has the following tile
types: Orange, Dark Green, Light Green, Black, Blue, White, Pink, Purple, Maroon and Red.</p>
        <p>After the user has defined the tile-set size and creating the training data, the WFC algorithm then
goes through the map and makes the tile-sets and assigning each of the tile-sets into an array. It is
important to note that in the figure 6 the tile-set 5 is a duplicate. The WFC does not update the array of
possible patterns with duplicate tile-sets.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.1.2. Creating Adjacency Rules</title>
        <p>From the array of patterns created, the BuildPropagator() function is used to create an index data
structure; this index is used by the system to describe how tile-set should fit next to one another.
’0’ : [’1’,’2’,”]
’1’ : [’0’,’2’,”]
’2’ : [’1’,’2’,”]
’3’ : [’4’,”,”]
’4’ : [’3’,”,”]
...</p>
        <p>This example is quite rudimentary/crude. However, it does illustrate the basic principle. If two tile-sets
can overlap one another, this information gets added to the index data structure stored as a valid rule.</p>
      </sec>
      <sec id="sec-3-4">
        <title>3.1.3. Generation Phase</title>
        <p>During the WFC generation phase, grid locations for the output grid; are continuously selected and
assigned. The user specifies the size of the output grid, and as the constraint solver works through the
grid, it keeps track of the tile-sets it has placed and their adjacency rules. Also, marking the areas of the
grid that have had tile-sets assigned to them and storing grid locations that need to have tile-sets set.</p>
        <p>The way this is achieved is by programmatically storing this information in a table. The variables
stored in this table are Boolean values; these values represent whether or not the algorithm has assigned
a pattern to a location within the output. The WFC output grid where true statements represent areas
that have not had a tile-set assigned to them, and false statements have had tile-sets assigned.</p>
        <p>As tile-sets are selected and placed within the WFC grid output, this action serves two purposes. It
reduces the unassigned variable’s index bringing the WFC algorithm closer to zero entropy and, in turn,
reducing the possible choices that can connect to the existing tile-sets which have already had tile-sets
assigned. In the event, the WFC algorithm encounters a conflict. It can locally backtrack on its output;
instead, a global reset occurs.</p>
        <p>As the WFC algorithm is filling in its output grid, it is simultaneously identifying unsigned tiles with
the lowest entropy, which refers to the lowest possible combinations of tile-sets that will fit in a given
position on the output grid. The grid location with the low entropy cost identified by the Observe()
function is selected. This function then chooses a tile-set that will fit into that position, given the
weighted average of tile-sets presented in the source data.</p>
        <p>After the observation function has chosen and placed a tile-set, the WFC output must be updated.
After placing a tile-set, the WFC algorithm then ensures that the placement of this new tile-set does not
break existing rules; it does this by checking the valid rule array in the Propagation() function.</p>
        <p>The propagation function does this by looping through all the output locations that have not reached
zero entropy until there are no locations left to update. Whilst it is going through each of the locations
on the output grid, it checks all of the neighbors of the currently selected location to ensure that the
pattern placed is still a valid option. If it isn’t, it flags that location for updates and removes its current
patterns from the possible options for that location.</p>
        <p>As stated earlier, with the placement of each tile-set, the ’entropy’ or left over tiles of the output area
in turn reduces. Once the entire output grid has reached zero entropy or there are no tiles left to solve,
the system is ready to produce the final output.</p>
      </sec>
      <sec id="sec-3-5">
        <title>3.1.4. Interaction Loop</title>
        <p>Once the data entry stage is completed and the initial kernel entry is finalized, Melete can use the WFC
algorithm to generate outputs. The user then enters the interaction loop, which can be divided into
four distinct stages: output selection, output mapping, output editing, and output testing. While in
the interaction loop, the user can switch between these stages at any time, allowing for a dynamic and
iterative design process.</p>
      </sec>
      <sec id="sec-3-6">
        <title>3.1.5. Output Selection</title>
        <p>During the output selection stage of the interaction loop, the user can cycle through multiple outputs
generated by the WFC algorithm, each based on the original kernel created during the data entry stage.
The user can review these outputs and save the ones they find most appealing for further refinement.</p>
      </sec>
      <sec id="sec-3-7">
        <title>3.1.6. Output Mapping</title>
        <p>Once the user chooses an output that matches the type of level they want to create, they move on to
the output mapping stage in Melete. In this stage, Melete fills in the selected output with gameplay
elements and environmental objects. As shown in figure 9, the system generates a preview of the
environment, placing trees, grass, and other game objects. These are scaled, rotated, and positioned
based on the user’s input and chosen design style. Melete also applies textures to the environment
according to the user’s settings. This stage gives the user a complete view of the level, helping them
better understand how the gameplay might look and feel.</p>
        <sec id="sec-3-7-1">
          <title>3.2. Output Editing</title>
          <p>In most cases, PCG algorithms may generate outputs that are close to what the user envisions but
may still contain errors. To address this, the user can disable the output mapping stage and switch to
the output editing stage. This stage allows the user to fine-tune the output to meet their needs while
eliminating much of the repetitive work involved in level design.</p>
          <p>During the output editing stage, the user interacts with a palette UI located on the right-hand side
of the output. This interface enables them to directly edit the WFC output. Additionally, the user can
modify the kernel used by the WFC algorithm based on their updated design. These changes not only
refine the current output but also serve to improve future generations of the WFC algorithm, aligning
them more closely with the user’s evolving design preferences.</p>
        </sec>
      </sec>
      <sec id="sec-3-8">
        <title>3.2.1. Output Testing</title>
        <p>In this stage, the user can play-test and explore their design using a player character, seamlessly
switching between editing and testing. Gaining this insight before releasing their design helps facilitate
an iterative design process.</p>
        <p>The dynamically updated 3D view enables immediate testing of modifications, providing an interactive
way to explore and evaluate the environment. At any point during the interaction loop, the user can
choose to view the design from the player’s perspective, ensuring a more polished and player-centric
result.</p>
        <p>In this version of the training data, we have used a combination of cyan, grey, and teal to indicate
where a staircase should be placed. As shown in figure 10 above, the system has recognized a special
case scenario, resulting in the placement of a ramp or staircase within the environment.</p>
        <p>In figure 11, we see that part of the special case scenario has been placed within the environment.
However, since the cyan element is not included in the map output, no stairs or ramp was generated.</p>
        <p>Melete is an innovative tool designed to assist human designers in the level design process. By utilizing
the WFC algorithm and a unique user interface, Melete enables users to create a 2D representation of a
level, which is then analyzed and stylistically replicated by the algorithm. Users can further manipulate
the WFC output to refine the design. The final step in Melete is the export process—if the user is satisfied
with the level, they can export an XML document containing the map structure. This document can
then be read by another system, allowing seamless integration of the designed map into a game.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Method</title>
      <p>When reviewing existing literature on MIAI pipelines, two distinct approaches emerged: evaluating the
PCG system’s output and conducting user studies to assess user experience. Given our focus on the
role of playtesting within the interaction loop, we determined that expert analysis would provide the
most nuanced feedback regarding participants’ experiences with Melete.</p>
      <p>To design the questions, we reviewed existing studies, though many MIAI systems mentioned user
studies without reporting the specific questions used. We tailored our questions based on the available
literature, resulting in the following:
• What did you like about the system?
• What did you dislike about the system?
• How easy was it to use the tool?
• Did you have enough control over the design process?
• Was the play testing mode useful?
To explore playtesting’s impact on the MIAI pipeline, we presented participants with two distinct design
challenges to highlight its role during the design process. We chose one top-down perspective and one
over-the-shoulder perspective, aligning with the design considerations for battle royale and real-time
strategy (RTS) games, respectively. These genres provided enough contrast to reveal how playtesting
influenced design workflows.</p>
      <p>To reach a consensus among experts, we conducted a semi-structured focus group after the Melete
sessions. The follow-up questions were:
• Do you think this is a useful tool?
• What was your workflow with the system?
For consistency, experts were introduced to Melete through a 15-minute recorded lecture and tutorial.
This session explained MIAI systems, provided an overview of the wave function collapse (WFC)
algorithm, and outlined its core functionality. After which they where given 15 minute sessions with
Melete to tackle each of the design challenges presented above. The primary research was available
during this time to answer any questions the participants had and provided the participants with a
hand out that included the main system controls.</p>
      <sec id="sec-4-1">
        <title>4.1. Participants</title>
        <p>The participants selected for this experiment were two experts academic designers, and one industry
expert designer, and two academic experts in AI.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5. Results and Data analysis</title>
      <p>In this section we will highlight some of the areas of interest from the results of our expert analysis of
Melete and our focus group results analysis.</p>
      <sec id="sec-5-1">
        <title>5.1. Question 1: What did you like about the system?</title>
        <sec id="sec-5-1-1">
          <title>5.1.1. Creativity</title>
          <p>One of the most notable similarities across both sessions was the emphasis on creativity. Participants
described the emergent structures generated by Melete as compelling and inspiring. Participant 1
encapsulated this sentiment by stating that “the emergent complexity of some environments can make
inspiring designs,” reflecting how the procedural generation capabilities of the system provided new
design avenues. Similarly, Participants 4 and 5 acknowledged the value of the “messy” terrain and the
satisfaction derived from interacting with procedural content generation (PCG). The narrative across
both design sessions suggests that Melete is perceived as a catalyst for creative exploration, enabling
designers to uncover novel configurations that may not have been considered through conventional
design processes.</p>
        </sec>
        <sec id="sec-5-1-2">
          <title>5.1.2. Collaborative</title>
          <p>Another recurring theme was the perception of collaboration between the designer and the system.
Participant 5 in both sessions underscored the experience of co-creating with Melete, describing it
as a “nice feeling of collaboration.” This reflects a broader narrative in which the designers did not
merely view Melete as a passive tool but rather as an interactive partner in the creative process. The
system’s ability to generate unexpected yet innovative results contributed to this collaborative sensation,
reinforcing the idea that Melete serves as an extension of the designer’s thought process rather than
just a utility.</p>
        </sec>
        <sec id="sec-5-1-3">
          <title>5.1.3. Design Iteration</title>
          <p>Both sessions underscored the utility of Melete for rapid prototyping and iteration. In the BR session,
participants appreciated the tool’s ability to facilitate prototyping and quickly modify generated maps.
Participant 4 noted how useful it was for generating prototyping environments, while Participant 5
highlighted the ease of editing generated maps. The RTS session also emphasized real-time editing
capabilities, with Participant 4 remarking that “being able to do live editing was cool.” This suggests
that, regardless of the game genre, Melete is valued for its ability to streamline the level design process
and ofer real-time adjustments that enhance workflow eficiency.</p>
        </sec>
        <sec id="sec-5-1-4">
          <title>5.1.4. Novelty and Inspiration</title>
          <p>
            The perception of novelty in Melete’s output emerged as a key aspect of its appeal. In the BR session,
Participant 1 emphasized how wave function collapse produced “compelling and often novel” spaces.
Similarly, Participant 2 recognized its potential for generating non-essential tile-based positional objects.
The RTS session echoed this sentiment, with Participant 3 highlighting the flexibility of tile colouring
and diversity of tile types. This suggests that Melete’s adaptability across diferent game genres fosters
Study
What did you like
about the system?
Procedural
generation in educational
games [
            <xref ref-type="bibr" rid="ref19">42</xref>
            ]
What did you
dislike about the
system?
How engaging and
unexpected did you
find the generated
game?
Was it more
inspiring when the
system output was
less/more similar to
your input?
To what extent is
the produced item
an example of the
artefact class in
question
How easy was it to
use the tool?
Not Reported
Not Reported
How could
enhancing/scaling
levels improve level
designers work
flow and fulfilling
their own design
goals
To what extent
did the interaction
in the game
accurately represent
and respond to
your intent
In which iteration
where you inspired
most, can you
explain why
To what extent is
the produced item
dissimilar from
what is currently
created by the
human user?
Were you able to
use the tool
without unnecessary
effort?
How did you use
the persistence
function?
Overall how
pleased are you
with the game
generated by the
tool
Do you have any
comments on the
interaction of a
computational
partner to inspire
you
To what extent
would the
produced item be of
use to end users?
Did you feel you
had enough control
over the generated
games?
What other AI/ML
functionality would
you like to see in a
tool like this.
How does the
produced item match
the human users
frame?
Was it fun?
Not Reported
Not Reported
Not Reported
          </p>
          <p>Not Reported</p>
          <p>Not Reported</p>
          <p>Not Reported</p>
          <p>Not Reported
Not Reported</p>
          <p>Not Reported</p>
          <p>Not Reported
innovative level design, presenting designers with unique configurations that might not emerge through
traditional methods. Both sessions highlighted how Melete’s unpredictability contributed to creative
inspiration. In the BR session, participants were particularly intrigued by how the system produced
unconventional structures—such as a two-story building with excessive staircases—that they would
not have conceptualized independently. Similarly, in the RTS session, Participant 4 appreciated the
“messy” terrain that suited a destroyed urban battlefield setting. Participant 5 described how Melete
“throws curveballs in its outputs” that stimulate creative thinking. This theme underscores the role of
Melete in broadening design perspectives and encouraging designers to explore unconventional spatial
arrangements.</p>
        </sec>
      </sec>
      <sec id="sec-5-2">
        <title>5.2. Question 2: What did you dislike about the system?</title>
        <p>5.2.1. PCG
Participants across both sessions raised concerns about the efectiveness and eficiency of the PCG
algorithm, emphasizing the need for significant manual intervention to achieve believable
environments. Participant 1 noted in the first session that substantial ”re-generation and artifact cleaning” was
necessary, indicating that the automated generation process produced inconsistencies requiring
correction. In the second session, they further elaborated that a ”small kernel size” limited the algorithm’s
ability to replicate larger formations beyond immediate adjacency. Similarly, Participant 2 expressed
dissatisfaction with the tile/grid-based nature of Melete, stating that ”Currently, it’s very tile-based in
all three axes.” This observation suggests that the rigid, grid-like Melete’s approach constrained organic
or free-form level design, which could reduce immersion and variety in both BR and RTS experiences.
Together, these insights highlight the ineficiencies in the Melete, which ultimately hindered automation
and increased the need for manual corrections. Reinforcing the idea that MIAI Pipelines do have a place
in design as purely “Online PCG” systems may not be suficient.</p>
        <sec id="sec-5-2-1">
          <title>5.2.2. User Interface and training</title>
          <p>The usability of the UI emerged as a significant point of friction among participants. Both Participant 4
and 5 found the interface unintuitive and cumbersome. Participant 4 described a ”disconnect in the UI,”
indicating that the interaction flow between diferent states was problematic. Participant 5 echoed these
sentiments, stating that the UI and input controls were ”a little fiddly” and required efort to remember
the correct sequences to perform desired actions.</p>
        </sec>
        <sec id="sec-5-2-2">
          <title>5.2.3. Navigation and Camera Control Issues</title>
          <p>Dificulties with navigation and camera controls further compounded usability challenges. Participant
5 described the camera and movement controls as ”sluggish,” noting that they interfered with their
ability to inspect levels efectively. This sluggishness hindered both the design process and playtesting,
making adjustments and refinements slower than necessary. Participant 4 suggested that incorporating
a minimap for better navigation would be beneficial. Additionally, RTS participants pointed out issues
with playtest agent movement, with Participant 3 stating that ”the movement of the agent in playtest is
not very accurate.” This inaccuracy diminished the reliability of play testing in that genera, making it
dificult to evaluate gameplay mechanics efectively.</p>
        </sec>
      </sec>
      <sec id="sec-5-3">
        <title>5.3. Question 3: How easy was it to use the tool?</title>
        <p>5.3.1. Ease of Use
In the BR session, Participant 1 noted, ”However, as a concept, the cyclic iteration process could become
easy to prototype spaces with.” Similarly, Participant 5 stated, ”Fairly easy - I understood the concept
quite quickly. Most of the issues came from trying to remember the interface elements and pressing the
wrong buttons.” Despite understanding the process, they faced dificulties with interaction mechanics.</p>
        <p>In the RTS session, similar sentiments were echoed. Participant 1 acknowledged, ”The current layout
is not intuitive, but the tool itself was straightforward enough to work with.” However, challenges arose
due to the scale of the sample map and limited tile options, leading to misaligned structures. Participant
2 further criticized the UI, stating, ”A bit cumbersome - a single pallet that was selectable would be
preferred over separate select buttons, index, and selectable palette.”</p>
        <sec id="sec-5-3-1">
          <title>5.3.2. UI and Workflow Challenges</title>
          <p>In the BR session, Participant 4 commented, ”There could be some more easing of the user experience
with tooltips, less complex inputs, and fewer clicks in between diferent desired actions.” Similarly,
Participant 1 stated, ”The current user interface is hard to use, with several steps and often unintuitive
interfaces.”</p>
          <p>The RTS session participants had similar complaints but focused more on specific aspects of the UI.
Participant 1 noted, ”The current layout is not intuitive,” while Participant 2 emphasized the need for a
more eficient tile selection system: ”A bit cumbersome - a single pallet that was selectable would be
preferred over separate select buttons.”</p>
        </sec>
        <sec id="sec-5-3-2">
          <title>5.3.3. User Adaptation Over Time</title>
          <p>Despite these challenges, both groups demonstrated adaptability as they became more accustomed
to the tool. Participants developed workarounds to streamline their workflows and mitigate usability
issues. In the BR session, Participant 5 remarked, ”Most of the issues came from trying to remember
the interface elements and pressing the wrong buttons.” Over time, they found ways to navigate these
dificulties.</p>
          <p>A similar pattern emerged in the RTS session, where Participant 5 stated, ”The concept is simple, and
I’m starting to get used to using it (tactics for feeding it, etc.), but some of the fiddly interaction aspects
are a bit more dificult than needed.” This demonstrates that while initial usability was an obstacle,
continued use led to increased familiarity and eficiency.</p>
          <p>Participant 4 suggested, ”An RTS probably needs two distinct enemy bases that the units originate
from, but having to manually add these into the map after random generation was harder than just doing
this by hand.” The ability to combine hand-designed bases with procedural generation was identified as
an optimal solution. In contrast, the BR session emphasized dificulties with navigation and workflow
eficiency. Participants suggested improvements such as mini-maps and smoother transitions between
perspectives.</p>
          <p>Participant 4 noted, ”There could be some more easing of the user experience with tooltips, less
complex inputs, and fewer clicks in between diferent desired actions.” Similarly, Participant 5 observed,
”Most of the issues came from trying to remember the interface elements and pressing the wrong
buttons.” These comments indicate that BR participants were primarily concerned with refining the
user experience rather than genre-specific functionality.</p>
          <p>Participant 4 stated, ”I understand it’s a prototype, so I’m basing my evaluation on that: there could be
some more easing of the user experience with tooltips, less complex inputs, and fewer clicks in between
diferent desired actions.” This suggests that they were willing to overlook some issues, provided they
could be resolved in later iterations.</p>
        </sec>
      </sec>
      <sec id="sec-5-4">
        <title>5.4. Question 4: Did you have enough control over the design process?</title>
        <sec id="sec-5-4-1">
          <title>5.4.1. Control Over the Design Process</title>
          <p>Participant 1 from the RTS session described the outcomes as ”substantially variable,” leading to
unintended elements such as long walls stretching across the map. This unpredictability constrained
their ability to fully utilize the tool’s potential. On the other hand, BR participants acknowledged
similar artifacts but found them more manageable within their design framework. Participant 1 from
BR mentioned that while artifacts existed, the ”wave function collapse algorithm” still allowed for some
consistency in design replication, reinforcing the idea that the tool ofered more usable outcomes in
this context.
5.4.2. PCG
Participant 4 articulated this challenge: ”Not being able to think about things like resource placement or
cover was a bit odd for the task of designing an RTS map.” This sentiment underscores a key limitation
in procedural generation: while it can inspire creativity, it lacks the ability to automatically generate
maps without requiring significant post-processing adjustments.</p>
          <p>Conversely, BR participants perceived the tool as more adaptable to their needs. The design
requirements of BR maps, which often emphasize large-scale layouts with scattered elements rather
than precise resource placements, allowed the procedural system to function more efectively. While
some participants noted issues with the algorithm, they generally felt they had enough control over
adjustments to make the results useful. For instance, Participant 4 noted that the tool was adequate for
”grayboxing a level,” even if additional features like power-ups and complex structures were needed.
This perspective suggests that MIAI tools such as Melete may be more efective in early-stage design.
5.4.3. Control
The perceived level of control over the design process was another diferentiating factor. BR participants
overwhelmingly felt they had enough influence over the final output. Participant 5 stated, ”I fed the
thing and had the final say on the output,” reinforcing the notion that despite MIAI system’s inherent
randomness, they still felt like the designers in control of the process. In contrast, RTS participants had
a mixed reaction. Some, like Participant 5, saw the tool as merely an inspiration mechanism rather than
a rigid determinant of the final design, comparing it to ”other techniques for driving creativity, like
randomization.” However, others, like Participant 2, simply answered ”no” when asked if they felt in
control.</p>
        </sec>
      </sec>
      <sec id="sec-5-5">
        <title>5.5. Question 5: Was the play testing mode useful?</title>
        <sec id="sec-5-5-1">
          <title>5.5.1. Play-test Navigation</title>
          <p>Participants in both sessions found playtesting efective in identifying map artifacts and rendering
inconsistencies. BR Participant 1 stated that playtesting allowed for rapid prototyping. Whilst, in the
RTS session, the same participant confirmed that playtesting efectively outlined artifacts and outliers,
helping refine map structures. Both genres benefited from playtesting’s diagnostic capabilities.</p>
        </sec>
        <sec id="sec-5-5-2">
          <title>5.5.2. Perspective</title>
          <p>BR participants found playtesting essential due to their game’s reliance on movement, exploration,
and 3D space awareness. Participant 5 described playtesting as ”essential” despite usability challenges,
while Participant 4 stressed the need for a minimap to maintain spatial awareness during level design.
In contrast, RTS participants found it less relevant since their game is typically viewed from a top-down
perspective. Participant 4 stated that ground-level playtesting was ”less useful” in an RTS context, as
the genre rarely adopts that perspective.</p>
        </sec>
      </sec>
      <sec id="sec-5-6">
        <title>5.6. Expert Focus Group discussion</title>
        <sec id="sec-5-6-1">
          <title>5.6.1. Question: do you think this is a useful tool?</title>
          <p>During the focus group the participants where asked: “Do you think this is a useful tool?” Participants
generally recognized the tool’s potential, particularly in mixed-initiative design, and iteration-based
workflows. However, they also identified key limitations, especially in its current prototype form.</p>
          <p>Participant 1 highlighted the significance of the tool’s integration with a mixed-initiative approach,
noting that its iterative feedback system could be a core innovation. However, they also pointed out that
artifacts frequently emerged, making it sometimes more practical to design elements by hand rather
than relying on the tool. Similarly, Participant 2 acknowledged its potential in rule system creation but
expressed concerns over its lack of flexibility in handling structured map designs.</p>
          <p>Participant 4 provided additional insight, emphasizing that while the tool was efective at generating
randomized content, it struggled in structured environments, such as RTS maps where controlled
layouts are necessary.
5.6.2. PCG
Participants found that the tool was more useful for certain game genres than others. Games that benefit
from randomized elements, such as RPGs, dungeon crawlers, and BR maps, were seen as more compatible
with the tool’s capabilities. In contrast, RTS games, which require precision and structured layouts,
posed significant challenges for the tool’s procedural approach. Participant 4 noted that while the
tool was useful for generating semi-randomized elements, it struggled with more formalized gameplay
structures. For example, an RTS typically requires two symmetrical bases with controlled pathways,
but the tool often produced chaotic noise instead of structured lanes. They suggested that while the tool
could generate useful background elements, it would require additional manual intervention to be viable
for RTS game design. Participant 5 echoed this sentiment, stating that while the tool had potential across
various design challenges, it was less suited for RTS levels due to its tendency to generate enclosed
rather than open spaces. Nonetheless, they believed the tool had utility in all examined scenarios, albeit
to varying degrees.</p>
        </sec>
        <sec id="sec-5-6-2">
          <title>5.6.3. Strengths in Generating Semi-Randomized Noise</title>
          <p>Despite its limitations in structured map design, the tool was seen as particularly strong in generating
procedural ”background noise.” Participants found it efective in creating environmental elements such
as forests, ruins, and scattered features, which are dificult to craft manually without appearing artificial.
Participant 4 reinforced this perspective, explaining that while the tool did not excel at structured RTS
maps, it performed well in generating randomized features for RPGs and BR games. The tool’s ability
to create organic-looking randomness was its key strength.</p>
        </sec>
        <sec id="sec-5-6-3">
          <title>5.6.4. Appreciation for Mixed-Initiative Design</title>
          <p>Several participants valued the mixed-initiative approach, which allowed users to refine and adjust
generated content instead of relying solely on automation. However, they also noted that the frequent
appearance of artifacts sometimes made manual design a more efective alternative.</p>
          <p>Participant 1 discussed how iterative refinement and feedback loops could be central to the tool’s
usability. They proposed that adding elements such as kernel size variability and randomized placements
could significantly improve the tool’s efectiveness.</p>
          <p>Overall, the MIAI tool has notable potential but is hindered by its current limitations. It is most
efective in generating semi-randomized environmental features but struggles with structured gameplay
elements and large tile-based maps. While participants valued its mixed-initiative approach, they also
encountered usability challenges that sometimes made manual design preferable.</p>
        </sec>
        <sec id="sec-5-6-4">
          <title>5.6.5. Question 2 focus group: What was your workflow with the system?</title>
          <p>During the focus group the participants where asked: “What was your workflow with the system?”
The use of the Melete among participants was characterized by an iterative, trial-and-error approach
where play, experimentation, and exploration were essential. Due to the unpredictable nature of the
Melete’s outputs, users engaged in cycles of input adjustment, observation, and refinement.</p>
        </sec>
        <sec id="sec-5-6-5">
          <title>5.6.6. Iterative Exploration as a Core Workflow</title>
          <p>Participants engaged with the tool in an iterative manner, repeatedly testing diferent inputs, analyzing
the outcomes, and adjusting their approach accordingly. Participant 1 described their workflow as a
”play-exploration cycle” where they engaged in trial and error to understand how their inputs translated
into visual outcomes. The unpredictability necessitated logical reasoning and puzzle-solving elements,
making the experience feel like a game rather than a straightforward design tool. They expressed
a desire for greater accuracy in input-to-output correspondence, believing that increased success in
replicating intended results would shift the process from play to structured design.</p>
          <p>Similarly, Participant 5 noted that their approach evolved as they became more familiar with the
system’s rules. Initially, their engagement was exploratory, but over time, they developed a more
intuitive sense of the tool’s behavior. They described the process as creative level design, where they
threw out ideas, observed results, and refined their approach through multiple iterations.</p>
        </sec>
        <sec id="sec-5-6-6">
          <title>5.6.7. Play testing</title>
          <p>A recurring theme among participants was the necessity of toggling between the designer and player
views to evaluate how the generated environments functioned in a gameplay context, this back-and-forth
movement was seen as essential.</p>
          <p>Participant 4 relied heavily on shifting perspectives, generating a random map, exploring it from a
player’s viewpoint, and then returning to the editor to refine elements that stood out. This iterative cycle
was particularly useful for assessing emergent gameplay features, such as discovering how randomly
generated structures (e.g., hallways and forests) contributed to level dynamics. However, they noted that
while the tool excelled at creating organic, procedurally generated content, more structured, intentional
designs required manual intervention. Participant 5 echoed this sentiment, stating that transitioning
between views was fundamental to their process.</p>
          <p>Overall, participants engaged with the tool through an iterative, experimental process, leveraging play
and exploration to understand its capabilities. While the system was well-suited for MIAI. Switching
between designer and player perspectives was a crucial but sometimes cumbersome aspect of the
workflow. Participants expressed a strong desire enhanced usability features to improve eficiency.
Despite these limitations, they recognized the tool’s potential for rapid prototyping.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>6. Discussion</title>
      <p>The two sessions—Battle Royale (BR) and Real-Time Strategy (RTS) — provides insight into the potential
usefulness of Melete as a design tool. The qualitative data reveal overarching themes across both
generas while also highlighting key diferences in the system’s application and user reception. By
examining participants feedback, we can discern the narrative underpinning their experiences and
expectations when using Melete.
6.1. Q1
6.2. Q2
In response to the question ”What did you like about the system?”, the two sessions illustrate Melete’s
value as a tool for fostering creativity, facilitating collaboration, and supporting rapid prototyping.
While both groups found Melete beneficial, their priorities difered based on game genre. BR participants
emphasized iterative design and immersive visualization, whereas RTS participants valued the real-time
editing and terrain flexibility. While many of the similarities highlight Melete’s strengths, key diferences
in the sessions reveal the varying demands of diferent game genres. The BR session placed greater
emphasis on playtesting and visualization, with participants valuing the 3D environment for interactive
exploration. The third-person camera controller was seen as an advantage in this setting. Conversely,
RTS participants prioritized real-time editing, finding value in the ability to modify maps dynamically,
which was also available to them in session one. This divergence indicates that while Melete is efective
in both scenarios, diferent genres require diferent functionalities, with RTS designers highlighting the
importance of being able to playtest with similar camera functionality as that of the intended genera.
In response to the question ”What did you dislike about the system?” Across both BR and RTS groups,
common pain points emerged regarding the ineficiencies of PCG, the UI, and navigation and camera
control issues. The excessive manual iteration required due to PCG constraints, the UI flow, and sluggish
camera movement collectively hampered the design and testing processes. While participants still found
aspects of the system enjoyable, these persistent limitations negatively impacted usability and eficiency
across both game genres. Addressing these concerns would be crucial for improving user experience,
streamlining workflow, and enhancing automation within the game development environment. An
additional challenge identified by participants was the lack of accessible, on-screen guidance. One
participant noted that while an introductory tutorial was available, it was not easily accessible for
reference during actual usage, making it dificult to recall necessary instructions. This lack of immediate
guidance contributed to ineficiencies in navigating the interface, increasing frustration and reducing
usability. Suggesting that not only do we need to consider how we develop MIAI tools, but how do we
approach training users to use them efectively as a possible avenue for study.
The third question we asked the experts during the BR and RTS sessions about the system was, How easy
was it to use the tool? Experts found the tool’s core functionality understandable but noted usability
challenges. BR participants struggled with UI complexity, navigation, and workflow ineficiencies,
though minor improvements like tooltips could ease use. RTS participants found some tasks, like adding
bases, more cumbersome than necessary and suggested prefabs for eficiency. Both groups agreed that
streamlining the UI, refining interactions, and adding genre-specific tools would significantly enhance
usability. Despite initial challenges, participants adapted over time, indicating Melete’s strong potential
with targeted refinements.
The fourth question we asked the experts during the BR and RTS sessions about the system was, did
you have enough control over the design process? Experts had mixed views on design control. In
the BR session, participants generally felt they had enough control despite grid-based constraints and
occasional artifacts. The system was valued for prototyping, though some game-specific features were
lacking. RTS participants had more varied experiences, with some finding the tool efective while others
faced unpredictable outputs and limited control over key design elements. Both groups agreed Melete
is a useful prototyping tool but requires refinement and manual intervention. This highlights the need
for genre-specific tailoring to ensure suficient control and predictability for diferent game design
paradigms.
The fith question we asked the experts during the BR and RTS sessions about the system was, Was the
play testing mode useful? Experts agreed that playtesting mode was valuable but more efective for BR
than RTS. BR participants praised its role in rapid space prototyping, though navigation challenges,
like the lack of a minimap and clunky character controls, limited its usability. RTS participants found it
helpful for visualizing maps and spotting artifacts but noted its limited relevance due to the genre’s
topdown perspective. Both groups saw playtesting as essential for refining designs, though BR participants
highlighted its broader potential for other genres, like dungeon crawlers. Overall, playtesting was more
impactful for exploration-heavy game formats like BR.</p>
    </sec>
    <sec id="sec-7">
      <title>7. Conclusion</title>
      <p>As highlighted in the background research and echoed by AI and design experts in this study, research
into HCI, PCG, and their integration within MIAI pipelines remains in its early stages and demands
greater focus. Understanding how diferent PCG algorithms impact MIAI workflows based on design
challenges could reveal significant obstacles. Additionally, exploring if and how MIAI users interact with
PCG algorithms may uncover opportunities in other areas of research such as LLM integration in MIAI
pipelines. From an HCI perspective, designing efective interaction loops could empower designers
to collaborate more efectively with AI in creative contexts. Another critical challenge is establishing
robust validation methods for MIAI pipelines. Advancing these areas will require collaborative eforts
across multiple disciplines, including AI, UX/UI, and HCI, to create impactful tools and frameworks for
both academia and industry.</p>
      <p>In conclusion, in this paper we have introduced Melete, a novel MIAI pipeline used for the development
of 3D virtual environment. Our expert analysis highlighted the critical role of playtesting in the design
process, emphasizing the need for genre-specific playtesting components within MIAI interaction
loops. Therefore, based on this paper’s analysis it is not only important to include playtesting tools
within MIAI pipelines, there must also be considerations as to genre-specific playtesteing tools being
included in any MIAI pipeline that focuses on the creative applications of MIAI systems. By addressing
usability challenges and enhancing user control, Melete demonstrates the potential for MIAI pipelines to
transform game design workflows, enhance designer engagement, facilitate iterative design processes,
and rapid prototyping of 3D environments. We further provide recommendations for future research,
encouraging exploration into user interaction, validation methods, and cross-disciplinary collaboration
to advance the development of efective and adaptable MIAI tools.</p>
    </sec>
    <sec id="sec-8">
      <title>8. Declaration on Generative AI</title>
      <p>During the preparation of this work, authors used ChatGPT and Grammarly for the following: grammar
and spellcheck. After using this tool/service, the authors, reviewed and edited the content as needed
and take full responsibility for the publication’s content.
[14] A. Summerville, J. R. Mariño, S. Snodgrass, S. Ontañón, L. H. Lelis, Understanding mario: an
evaluation of design metrics for platformers, in: Proceedings of the 12th international conference
on the foundations of digital games, 2017, pp. 1–10.
[15] O. Withington, M. Cook, L. Tokarchuk, On the evaluation of procedural level generation systems,
in: Proceedings of the 19th International Conference on the Foundations of Digital Games, 2024,
pp. 1–10.
[16] B. Shneiderman, Supporting creativity with advanced information-abundant user interfaces,</p>
      <p>Springer, 2001.
[17] S. G. Isaksen, D. J. Trefinger, Celebrating 50 years of reflective practice: Versions of creative
problem solving, The Journal of Creative Behavior 38 (2004) 75–101.
[18] S. G. Isaksen, D. J. Trefinger, Creative problem solving, The Basic Course. New York: Bearly</p>
      <p>Limited (1985).
[19] B. Shneiderman, Creating creativity: user interfaces for supporting innovation, ACM Transactions
on Computer-Human Interaction (TOCHI) 7 (2000) 114–138.
[20] A. Liapis, G. N. Yannakakis, J. Togelius, Designer modeling for sentient sketchbook, in: 2014 IEEE</p>
      <p>Conference on Computational Intelligence and Games, IEEE, 2014, pp. 1–8.
[21] A. Hoyt, M. Guzdial, Y. Kumar, G. Smith, M. O. Riedl, Integrating automated play in level
cocreation, arXiv preprint arXiv:1911.09219 (2019).
[22] W. Gaver, What should we expect from research through design?, in: Proceedings of the SIGCHI
conference on human factors in computing systems, 2012, pp. 937–946.
[23] J. Zimmerman, J. Forlizzi, S. Evenson, Research through design as a method for interaction design
research in hci, in: Proceedings of the SIGCHI conference on Human factors in computing systems,
2007, pp. 493–502.
[24] E. Stolterman, The nature of design practice and implications for interaction design research,</p>
      <p>International Journal of Design 2 (2008).
[25] S. Margarido, P. Machado, L. Roque, P. Martins, Let’s make games together: Explainability in
mixed-initiative co-creative game design, in: 2022 IEEE Conference on Games (CoG), IEEE, 2022,
pp. 638–645.
[26] F. A. Figoli, F. Mattioli, L. Rampino, Artificial intelligence in the design process: The Impact on</p>
      <p>Creativity and Team Collaboration, FrancoAngeli, 2022.
[27] R. Pandya, S. H. Huang, D. Hadfield-Menell, A. D. Dragan, Human-ai learning performance in
multi-armed bandits, in: Proceedings of the 2019 AAAI/ACM Conference on AI, Ethics, and
Society, 2019, pp. 369–375.
[28] G. Zhang, A. Raina, J. Cagan, C. McComb, A cautionary tale about the impact of ai on human
design teams, Design Studies 72 (2021) 100990.
[29] J. Liao, P. Hansen, C. Chai, A framework of artificial intelligence augmented design support,</p>
      <p>Human–Computer Interaction 35 (2020) 511–544.
[30] G. Lai, F. F. Leymarie, W. Latham, On mixed-initiative content creation for video games, IEEE</p>
      <p>Transactions on Games 14 (2022) 543–557.
[31] T. Machado, D. Gopstein, A. Wang, O. Nov, A. Nealen, J. Togelius, Evaluation of a recommender
system for assisting novice game designers, in: Proceedings of the AAAI Conference on Artificial
Intelligence and Interactive Digital Entertainment, volume 15, 2019, pp. 167–173.
[32] P. Lucas, C. Martinho, Stay awhile and listen to 3buddy, a co-creative level design support tool.,
in: ICCC, 2017, pp. 205–212.
[33] A. Liapis, G. N. Yannakakis, Boosting computational creativity with human interaction in
mixedinitiative co-creation tasks (2016).
[34] G. Smith, J. Whitehead, M. Mateas, Tanagra: A mixed-initiative level design tool, in: Proceedings
of the Fifth International Conference on the Foundations of Digital Games, 2010, pp. 209–216.
[35] M. Guzdial, N. Liao, J. Chen, S.-Y. Chen, S. Shah, V. Shah, J. Reno, G. Smith, M. O. Riedl, Friend,
collaborator, student, manager: How design of an ai-driven game level editor afects creators, in:
Proceedings of the 2019 CHI conference on human factors in computing systems, 2019, pp. 1–13.
[36] Z. Zhou, M. Guzdial, Toward co-creative dungeon generation via transfer learning, in: Proceedings
Participant 2
Participant 3</p>
      <p>Session 1 Battle Royale Session 2
When wave function collapse
generates building spaces, the
emergent structures and spaces Program does successfully
feel compelling and often novel generate multi-level systems,
- there’s an element of so long as WFC arrangement
unconventional square matrix is set up correctly. The
space design which can feel emergent complexity of some
surreal and engaging. environments can make
For square matrix environments, inspiring designs that a
like Manhattan style cities this human could further interpret.
could construct some believable
and complex scenes
I like the way it learns patterns
and rules that can then
ibphnere-olgrpmeaipnmislgieecc.aarItseteaadsthewaounawtyoosnoms-feoasmtsiecenaltliyal caSuylrismrteeinmtttofhoabrsmepu.rsoemfuisleinbuitts up to
tile-based positional objects.
and landscape/areas
iceTwshnhoreverecilaridkmolilndnymmegaseettirghtnsrneitavcfeoti3rvde. caoTonfhldteoiluftelhreitexnyigdpbieipvlsiertoryscioetsfysthe
I generally like level editors
and I enjoy building levels, Being able to do live
so this was something that I editing was cool. I
like doing for fun, and also did like that I could
partially what I was conceivably have
comparing the system to. In used this to think
that sense it’s enjoyable to about both the unit
use, and I can also see it level from the third
being useful from the person perspective
perspective of generating and then also from
graybox prototypes. One a further remove
example of this was the map perspective.
totally random generation I liked that it
of a two story building generated a bunch
that had tons of staircases. of ”messy” terrain
This isn’t something that I in the center of the
would have ever made on map, which seems
my own, but it made me like it would fit
think divergently about what I’d want for a
what this would be like in destroyed urban
a Battle Royale context, battleground setting.
which was cool.</p>
      <p>It’s satisfying to feed an
PCG system and see
what it produces - a good
sense of agency attached
to my actions. The loop is
nice and quick, also, so I
can tinker and see the
results satisfyingly quickly.</p>
      <p>Editing the generated maps
is also nice - a sense of
collaboration with the
system/myself.</p>
      <p>The sense of feeding
a PCG system and
seeing the results is
quite satisfying. It’s
a nice feeling of
collaboration with
the system/myself.</p>
      <p>I give it what I think
will help with the
level generation and
it throws curveballs
in its outputs that I
think can stir creativity.
As with most waveform
collapse systems, a lot of
re-generation and artefact
cleaning is necessary to
make a believable
environment; a lot of
itteration, trial and testing
is needed to make a quite
low complexity scenes
Currently its very tile-based
in all three axes. Hard to
see how it could improve on
existing tile based solutions
outside of the ability to
change non-essential tiles
and neatly handle multiple
gridheight (e.g 8 or more)
or granular height (such
as on a 3D terrain, or
multiple grids and items
that don’t fit a specific
regular grid.</p>
      <p>Cannot find any at the
moment
The disconnect in the UI
was a problem sometimes.</p>
      <p>This was most apparent
because of the wide array
of button presses to get to
various editing states.</p>
      <p>There was also an issue
with me wanting to have a
little more onscreen
guidance in the editing
screen rather than having
it as an intro I couldn’t
easily refer back to. I also
Participant 4 found myself wanting the
ability to seamlessly switch
perspectives, maybe using
something like a minimap,
to let me know where I was
in the playtest scene. This
would help me to do what I
do in actual prototyping,
which is to go to an area,
take a look around from the
perspective of a player, make
some changes based on an
intuition, and then come back
in to see how it feels.</p>
      <p>The UI and inputs are a little
fiddly and I found it tricky
to remember what does
what and what order to
click things in to take my
desired action. The character
/camera controller is also a
bit sluggish and gets in the
way a little - I want to be
able to more easily inspect
my level.</p>
      <p>Participant 5</p>
      <p>Session 2
Likely due to a small kernal
size, forms larger than
immediate adjacency are
not efectively replicated.</p>
      <p>Successful replication of
layout complexity usually
only comes after a large
enough number of
generations that the
afordance of the
automation are lost,
though some pipeline
optimisation could help
make this tool become
more of a utility.</p>
      <p>Lack of ability to define
areas as to be randomised
and areas where a specific
arrangement is required.</p>
      <p>The movement of the
agent in play test is
not very accurate
This was a lot harder
to design for an RTS
because it didn’t have
as many of the
afordances I’d need
to think about in a
game like this
resource nodes,
defensible positions,
spawns, etc. I could
sort of imagine where
these would be, but it
was harder to fit the
genre constraints for
RTS into this system
than it was Battle
Royale. This was
especially the case in
terms of sight lines.</p>
      <p>The camera
perspective in a battle
royale is much
diferent from the one
in an RTS (which
tends to be further
remove isometric), so
thinking about
interesting sight lines
and landmarks was a
lot harder in practice.</p>
      <p>It’s a bit fiddly to
interact with - the UI
and input bindings.</p>
      <p>In some ways, the
”extra steps” on
generating a level
could slow things
down I suppose, but
that’s mitigated by
the fun of the
experience.</p>
      <p>Table 2
Question 2: What did you dislike about the system?</p>
      <p>Session 1
The current user interface is hard to use, several steps
and often unintuitive interfaces. However, as a concept,
the cyclic iteration process could become easy to prototype
spaces with
Straigghtforward - a little flakey from a user perspective(e..g having
to select the sample button before selecting the tile type to be placed.</p>
      <p>Hard to see though how it could use meaningfully a pallete of
hundreds of tiles as would be present in any grid-based or 2d isometric
game.ric
It’s very intuitive and easy to use
I understand it’s a prototype, so I’m basing my evaluation on that: there
could be some more easing of the user experience with tooltips, less
complex inputs, and fewer clicks in between diferent desired actions.</p>
      <p>However, keeping in mind that these would be fairly simple to add, I
think that the process was very straightforward and usable once I
understood the basic interactions.</p>
      <p>Fairly easy - I understood the concept quite quickly. Most of the issues
came from trying to remember the interface elements and pressing the
wrong buttons (etc.).</p>
      <p>Session 2
The current layout is not intuitive, but the tool itself was
straightforward enough to work with. The scale of the
sample map and the limited number of tiles more often
produces structures unaligned with the prompt than not.</p>
      <p>A bit cumbersome - a single pallet that was selectable
would be preferred over seperate select buttons, index
and selectable pallete
fairly easy to understand and use
This was again made harder by the tool. An RTS probably
needs two distinct enemy bases that the units originate from,
but having to manually add these in to the map after random
generation was harder than just doing this by hand. This is
where a pre-fab option might be handy. I could completely
hand design two diferent factional bases, and then use the
proc gen to make a battlefield, and then combine the two,
which would be the best of both worlds to me.</p>
      <p>The concept is simple and I’m starting to get used to using it
(tactics for feeding it, etc.), but some of the fiddly interaction
aspects are a bit more dificult than needed.
Yes</p>
      <p>Participant 5 I think so. I fed the thing and had the final say on the output.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>S.</given-names>
            <surname>Amershi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Cakmak</surname>
          </string-name>
          , W. B.
          <string-name>
            <surname>Knox</surname>
          </string-name>
          , T. Kulesza,
          <article-title>Power to the people: The role of humans in interactive machine learning</article-title>
          ,
          <source>AI</source>
          magazine
          <volume>35</volume>
          (
          <year>2014</year>
          )
          <fpage>105</fpage>
          -
          <lpage>120</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <given-names>T.</given-names>
            <surname>Lubart</surname>
          </string-name>
          ,
          <article-title>How can computers be partners in the creative process: classification and commentary on the special issue</article-title>
          ,
          <source>International journal of human-computer studies 63</source>
          (
          <year>2005</year>
          )
          <fpage>365</fpage>
          -
          <lpage>369</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <given-names>J.</given-names>
            <surname>Togelius</surname>
          </string-name>
          ,
          <string-name>
            <given-names>G. N.</given-names>
            <surname>Yannakakis</surname>
          </string-name>
          ,
          <string-name>
            <given-names>K. O.</given-names>
            <surname>Stanley</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Browne</surname>
          </string-name>
          ,
          <article-title>Search-based procedural content generation: A taxonomy and survey</article-title>
          ,
          <source>IEEE Transactions on Computational Intelligence and AI in Games</source>
          <volume>3</volume>
          (
          <year>2011</year>
          )
          <fpage>172</fpage>
          -
          <lpage>186</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <given-names>N.</given-names>
            <surname>Shaker</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Shaker</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Togelius</surname>
          </string-name>
          ,
          <string-name>
            <surname>Ropossum:</surname>
          </string-name>
          <article-title>An authoring tool for designing, optimizing and solving cut the rope levels</article-title>
          ,
          <source>in: Proceedings of the AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment</source>
          , volume
          <volume>9</volume>
          ,
          <year>2013</year>
          , pp.
          <fpage>215</fpage>
          -
          <lpage>216</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>H.</given-names>
            <surname>Yu</surname>
          </string-name>
          ,
          <article-title>Reflection on whether chat gpt should be banned by academia from the perspective of education and teaching</article-title>
          ,
          <source>Frontiers in Psychology</source>
          <volume>14</volume>
          (
          <year>2023</year>
          )
          <fpage>1181712</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [6]
          <string-name>
            <given-names>S.</given-names>
            <surname>Deterding</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Hook</surname>
          </string-name>
          ,
          <string-name>
            <given-names>R.</given-names>
            <surname>Fiebrink</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Gillies</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Gow</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Akten</surname>
          </string-name>
          ,
          <string-name>
            <given-names>G.</given-names>
            <surname>Smith</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Liapis</surname>
          </string-name>
          ,
          <string-name>
            <given-names>K.</given-names>
            <surname>Compton</surname>
          </string-name>
          ,
          <article-title>Mixed-initiative creative interfaces</article-title>
          ,
          <source>in: Proceedings of the 2017 CHI Conference Extended Abstracts on Human Factors in Computing Systems</source>
          ,
          <year>2017</year>
          , pp.
          <fpage>628</fpage>
          -
          <lpage>635</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <given-names>L.</given-names>
            <surname>Mamykina</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L.</given-names>
            <surname>Candy</surname>
          </string-name>
          , E. Edmonds,
          <article-title>Collaborative creativity</article-title>
          ,
          <source>Communications of the ACM</source>
          <volume>45</volume>
          (
          <year>2002</year>
          )
          <fpage>96</fpage>
          -
          <lpage>99</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [8]
          <string-name>
            <given-names>S. J.</given-names>
            <surname>Russell</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.</given-names>
            <surname>Norvig</surname>
          </string-name>
          ,
          <article-title>Artificial intelligence: a modern approach</article-title>
          , Pearson,
          <year>2016</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          [9]
          <string-name>
            <given-names>P.</given-names>
            <surname>Toprac</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Heng</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Siddharthan</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Tseng</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Abraham</surname>
          </string-name>
          , E. Vouga,
          <article-title>Automation of aaa game development using ai (</article-title>
          <year>2025</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [10]
          <string-name>
            <given-names>A.</given-names>
            <surname>Drachen</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.</given-names>
            <surname>Mirza-Babaei</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L. E.</given-names>
            <surname>Nacke</surname>
          </string-name>
          , Games user research, Oxford University Press,
          <year>2018</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          [11]
          <string-name>
            <given-names>A.</given-names>
            <surname>Canossa</surname>
          </string-name>
          ,
          <string-name>
            <given-names>G.</given-names>
            <surname>Smith,</surname>
          </string-name>
          <article-title>Towards a procedural evaluation technique: Metrics for level design</article-title>
          ,
          <source>in: The 10th International Conference on the Foundations of Digital Games</source>
          , sn,
          <year>2015</year>
          , p.
          <fpage>8</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          [12]
          <string-name>
            <given-names>M.</given-names>
            <surname>Cook</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Gow</surname>
          </string-name>
          ,
          <string-name>
            <given-names>G.</given-names>
            <surname>Smith</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Colton</surname>
          </string-name>
          , Danesh:
          <article-title>Interactive tools for understanding procedural content generators</article-title>
          ,
          <source>IEEE Transactions on Games</source>
          <volume>14</volume>
          (
          <year>2021</year>
          )
          <fpage>329</fpage>
          -
          <lpage>338</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          [13]
          <string-name>
            <given-names>A.</given-names>
            <surname>Liapis</surname>
          </string-name>
          ,
          <volume>10</volume>
          years of the pcg workshop: Past and future trends,
          <source>in: Proceedings of the 15th International Conference on the Foundations of Digital Games</source>
          ,
          <year>2020</year>
          , pp.
          <fpage>1</fpage>
          -
          <lpage>10</lpage>
          . of the 16th
          <source>International Conference on the Foundations of Digital Games</source>
          ,
          <year>2021</year>
          , pp.
          <fpage>1</fpage>
          -
          <lpage>9</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          [37]
          <string-name>
            <given-names>O.</given-names>
            <surname>Delarosa</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Dong</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Ruan</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Khalifa</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Togelius</surname>
          </string-name>
          ,
          <article-title>Mixed-initiative level design with rl brush</article-title>
          ,
          <source>in: Artificial Intelligence in Music</source>
          , Sound, Art and Design: 10th International Conference, EvoMUSART
          <year>2021</year>
          ,
          <article-title>Held as Part of EvoStar 2021</article-title>
          ,
          <string-name>
            <given-names>Virtual</given-names>
            <surname>Event</surname>
          </string-name>
          , April 7-
          <issue>9</issue>
          ,
          <year>2021</year>
          , Proceedings 10, Springer,
          <year>2021</year>
          , pp.
          <fpage>412</fpage>
          -
          <lpage>426</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          [38]
          <string-name>
            <given-names>G.</given-names>
            <surname>Todd</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Earle</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M. U.</given-names>
            <surname>Nasir</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M. C.</given-names>
            <surname>Green</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Togelius</surname>
          </string-name>
          ,
          <article-title>Level generation through large language models</article-title>
          ,
          <source>in: Proceedings of the 18th International Conference on the Foundations of Digital Games</source>
          ,
          <year>2023</year>
          , pp.
          <fpage>1</fpage>
          -
          <lpage>8</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          [39]
          <string-name>
            <given-names>R.</given-names>
            <surname>Gallotta</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Liapis</surname>
          </string-name>
          , G. Yannakakis,
          <article-title>Consistent game content creation via function calling for large language models</article-title>
          ,
          <source>in: 2024 IEEE Conference on Games (CoG)</source>
          , IEEE,
          <year>2024</year>
          , pp.
          <fpage>1</fpage>
          -
          <lpage>4</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          [40]
          <string-name>
            <given-names>N.</given-names>
            <surname>Sturtevant</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Decroocq</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Tripodi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Yang</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Guzdial</surname>
          </string-name>
          ,
          <article-title>A demonstration of anhinga: A mixed-initiative epcg tool for snakebird</article-title>
          ,
          <source>in: Proceedings of the AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment</source>
          , volume
          <volume>16</volume>
          ,
          <year>2020</year>
          , pp.
          <fpage>328</fpage>
          -
          <lpage>330</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation>
          [41]
          <string-name>
            <given-names>D.</given-names>
            <surname>Bhaumik</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Togelius</surname>
          </string-name>
          ,
          <string-name>
            <given-names>G. N.</given-names>
            <surname>Yannakakis</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Khalifa</surname>
          </string-name>
          ,
          <article-title>Lode enhancer: Level co-creation through scaling</article-title>
          ,
          <source>in: Proceedings of the 18th International Conference on the Foundations of Digital Games</source>
          ,
          <year>2023</year>
          , pp.
          <fpage>1</fpage>
          -
          <lpage>8</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation>
          [42]
          <string-name>
            <given-names>V.</given-names>
            <surname>Kumaran</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            <surname>Carpenter</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Rowe</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Mott</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Lester</surname>
          </string-name>
          ,
          <article-title>Procedural level generation in educational games from natural language instruction</article-title>
          ,
          <source>IEEE Transactions on Games</source>
          (
          <year>2024</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation>
          [43]
          <string-name>
            <given-names>M.</given-names>
            <surname>Kreminski</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Dickinson</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Osborn</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Summerville</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Mateas</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Wardrip-Fruin</surname>
          </string-name>
          ,
          <article-title>Germinate: A mixed-initiative casual creator for rhetorical games</article-title>
          ,
          <source>in: Proceedings of the AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment</source>
          , volume
          <volume>16</volume>
          ,
          <year>2020</year>
          , pp.
          <fpage>102</fpage>
          -
          <lpage>108</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref21">
        <mixed-citation>
          [44]
          <string-name>
            <given-names>I.</given-names>
            <surname>Karth</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A. M.</given-names>
            <surname>Smith</surname>
          </string-name>
          ,
          <article-title>Wavefunctioncollapse is constraint solving in the wild</article-title>
          ,
          <source>in: Proceedings of the 12th International Conference on the Foundations of Digital Games</source>
          ,
          <year>2017</year>
          , pp.
          <fpage>1</fpage>
          -
          <lpage>10</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref22">
        <mixed-citation>
          [45]
          <string-name>
            <surname>J. R. van Meter</surname>
          </string-name>
          ,
          <article-title>Schrödinger-newton 'collapse'of the wavefunction</article-title>
          ,
          <source>Classical and Quantum Gravity</source>
          <volume>28</volume>
          (
          <year>2011</year>
          )
          <fpage>215013</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref23">
        <mixed-citation>
          [46]
          <string-name>
            <given-names>I.</given-names>
            <surname>Karth</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A. M.</given-names>
            <surname>Smith</surname>
          </string-name>
          ,
          <article-title>Wavefunctioncollapse is constraint solving in the wild</article-title>
          ,
          <source>in: Proceedings of the 12th International Conference on the Foundations of Digital Games</source>
          , FDG '17,
          <string-name>
            <surname>Association</surname>
          </string-name>
          for Computing Machinery, New York, NY, USA,
          <year>2017</year>
          . URL: https://doi.org/10.1145/3102071.3110566. doi:
          <volume>10</volume>
          .1145/3102071.3110566.
        </mixed-citation>
      </ref>
      <ref id="ref24">
        <mixed-citation>
          [47]
          <string-name>
            <given-names>P.</given-names>
            <surname>Karimi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Rezwana</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Siddiqui</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M. L.</given-names>
            <surname>Maher</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Dehbozorgi</surname>
          </string-name>
          ,
          <article-title>Creative sketching partner: an analysis of human-ai co-creativity</article-title>
          ,
          <source>in: Proceedings of the 25th international conference on intelligent user interfaces</source>
          ,
          <year>2020</year>
          , pp.
          <fpage>221</fpage>
          -
          <lpage>230</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref25">
        <mixed-citation>
          [48]
          <string-name>
            <given-names>N.</given-names>
            <surname>Shaker</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Abou-Zleikha</surname>
          </string-name>
          ,
          <article-title>Alone we can do so little, together we can do so much: A combinatorial approach for generating game content</article-title>
          ,
          <source>in: Proceedings of the AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment</source>
          , volume
          <volume>10</volume>
          ,
          <year>2014</year>
          , pp.
          <fpage>167</fpage>
          -
          <lpage>173</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref26">
        <mixed-citation>
          [49]
          <string-name>
            <given-names>A.</given-names>
            <surname>Baldwin</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Dahlskog</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J. M.</given-names>
            <surname>Font</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Holmberg</surname>
          </string-name>
          ,
          <article-title>Towards pattern-based mixed-initiative dungeon generation 20506 (</article-title>
          <year>2017</year>
          )
          <fpage>1</fpage>
          -
          <lpage>10</lpage>
          . doi:
          <volume>10</volume>
          .1145/3102071.3110572.
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>