Abstract Forward Models for Modern Games

Lead Research Organisation: Queen Mary University of London
Department Name: Sch of Electronic Eng & Computer Science

Abstract

The games industry is one of the fastest-growing industries in the world, with yearly revenues expected to increase from US$ 138bn in 2018 to US$ 180bn in 2021. The UK games industry is a worldwide leader that contributes significantly to wealth creation and export, with a clear growing tendency: 62% of the 2261 companies in the UK were founded in the last 8 years. Employing 12,000 people with sales valued in £4.3bn for 2017, this industry is the second largest market in Europe and the fifth in the world.

Games have also been excellent benchmarks for the advancement of AI. One of the most clear and recent examples of this is the progress on search methods in the game of Go. Go is a thousand years old board game of simple rules but complex strategy, where humans had dominated computer AIs since the beginning of the field. Monte Carlo Tree Search (MCTS), an AI technique that explores the different branches of actions that both players can take, became in 2016 the standard algorithm for creating Go AI players, giving birth to substantial research on variations and applications of this algorithm. Since then, MCTS has been used in thousands of other works in and outside games. This progress reached another milestone when Google Deepmind's Alpha Go mastered this game with a combination of MCTS and Deep Learning (DL).

MCTS uses a forward model (FM), which is a representation of the game state that allows to roll the state forward after applying any action in the game. This "simulator" is also used by other Statistical Forward Planning (SFP) methods that are also showing similar promise to MCTS in some domains, such as Rolling Horizon Evolutionary Algorithms (RHEA). It is however striking that despite the popularity and progress on SFP methods, they have barely reached the games industry. The most known uses of MCTS for Opponent AI in the games industry are in the Total War series by Creative Assembly, AI Factory on card games and Lionhead's tactical planning for Fable Legends. Given that the games industry is one of the fastest growing industries in the world and UK one may wonder why one of the top algorithms on AI in Games barely reaches far less than 0.01% of this industry.

The aim of this project is to incorporate an FM library into a modern games engine in order to facilitate research on the use of SFP techniques in large, complex, video-games. On the one hand, the project will address the technical and design problems of integrating a customisable FM that determines which elements of the real game state form part of the FM and how abstractions can be made. On the other hand, the project will aim to understand how SFP methods perform under these conditions in complex and large commercial-like games, investigating how these can be improved. The resultant framework will allow to test these methods in a wide range of games, with a special emphasis on proposing a Game AI competition for industry and researchers. Dissemination of the project's research outcomes will be guaranteed via open source libraries, frameworks, documentation and scientific papers.

This project builds naturally on the PI's recent work on GVGAI (for which he is main developer, organiser and coordinator of the competition, tracks and team - www.gvgai.net), and it proposes a step change on General Game AI research and its relevance to the games industry, adapting it to modern games. This project addresses directly the applicability of well-established methods such as MCTS/RHEA to large and complicated games and also the industry needs for fast, reliable and state of the art AI techniques. Our strong group of game industry partners (Microsoft Research, AI Factory, Bossa Studios, Creative Assembly and Gwaredd Mountain) will help steer the project into the interests of the game research and industry communities. Applications beyond games will also be explored with the help of our non-game industry partner (the Defence Science and Technology Laboratory).

Planned Impact

The SCIENTIFIC COMMUNITY will benefit from this research. The AI in games community will benefit from having the possibility of testing their methods in commercial-like games. Having forward models in a large-scale games engine allows for research, across multiple game genres, the application of Statistical Forward Planning methods in complex environments. Researchers will benefit from being able to easily incorporate off-the-shelf advanced AI methods for non-player characters in complex game and non-game environments.

A project page to disseminate the findings and download the software, documentation deliverables and papers produced will be set up. Data from game logs for authorial analysis and explainability will be provided to build a large-scale database of high-quality data for new behavioural insights. Papers will be submitted to high impact factor journals on games (IEEE Transactions on Games) and evolutionary computation (IEEE Transactions on Evolutionary Computation), and also presented at most relevant conferences such as IEEE Conference on Games (CoG) or the AAAI Artificial Intelligence for Interactive Digital Entertainment (AIIDE). Special sessions, workshops and tutorials will be proposed for these venues. The international competition proposed will provide a great exposure of the project and the research breakthroughs achieved.

The VIDEO-GAMES INDUSTRY is a primary beneficiary of this proposal. The work performed will enable game companies to embed the latest AI methods in complex games, producing more interesting, challenging and fun games. The availability of stronger and better AI will reduce development time and costs and ease the automation of game evaluation and testing. By bringing the latest research to the industry, this project means a step change in the ways AI is applied in games, taking UK to a leading position in this industry. The hosting institution, QMUL, is part of the EPSRC IGGI CDT (EP/L015846/1) and its recent renewal. The goals and strategy of both IGGI and the Game AI group are closely aligned with this project: bringing the latest research in games to the industry.

Impact will be achieved by developing and providing an open source software library for an industry-standard game engine. The AI algorithms developed during the project will be publicly available on the project website. Given the popularity of the games engine and programming language within the games developers community, the reach of the implemented software is large. A direct impact mechanism is the possibility of an internship of the PhD student in Creative Assembly, one of the project partners, where our research findings can be applied. We'll present and promote our work at conferences with strong industry presence, such as Develop, the London Game AI Meetup and CoG.

The EDUCATION PROGRAMMES, concretely Computer Games and Computer Science degrees with modules on games and AI, will benefit from this research. Final year and MSc projects, and PhD topics will be able to use our framework for further research on Game AI. The PI has experience in this model, as his previous benchmark (GVGAI) has been used for teaching and as a base for student projects. GVGAI also showed that the proposed competition is a great asset for education, with multiple students across the globe participating in the challenges as part of their modules or projects. The integration of the framework with a game engine will aid the creation of more interesting games at game jams.

The project will produce interest among the GENERAL PUBLIC and media. The project will be promoted in showcase events, general interest articles (i.e MCV/Develop/ The Conversation) and regular press releases. The work will be promoted in public lectures and university open days. The team will also actively participate in events or magazines dedicated to the dissemination of research to the general public, such as Pint of Science nights or the CS4Fun Magazine.
 
Description During this project, the team investigated ways in which decision making can be done in complex environments. We employed turn-based strategy games, are these present scenarios where the decisions to be made at every turn of the game are of a very complex nature. The amount of situations a player can found themself is vast, and the range of actions to be make is pretty large.
We report findings in two different aspects: first, on the action space, which determines the amount of possible moves a player can make, by showing that action-abstraction methods (i.e. portfolio) are able to simplify the action space without being detrimental to the quality of the action-decision made. Besides, we also demonstrated that these methods can be use to achieve different play-styles, which translates to different alternative ways to solving the problem of decision making.
Secondly, we report findings on the state space. This is, we proposed a novel algorithm for decision making that analyses future possible game states and groups them together in equivalent clusters, so that each cluster represents a possible outcome of the game if the playing agent takes actions that lead to such states.

Overall, the findings in this project advanced the state of the art of AI decision making in complex scenarios.
Exploitation Route The complexity of the scenarios (i.e. games used) is medium-high. We did not have the time to research in more complex games (such as Total War or Starcraft), so investigating action decision-making in those very complex environments is still an open question.

The actual algorithms, however, can be used for decision making in moderately complex scenarios, such as games with medium-sized state and action spaces.
Sectors Creative Economy,Digital/Communication/Information Technologies (including Software)

 
Title Stratega 
Description Stratega aims to provide a fast and flexible framework for researching AI in complex strategy games. Games are configured using YAML-files and can be played through a GUI or by agents using an API. Stratega allows creating a wide variety of turn-based and real-time strategy games. Due to the flexibility of using YAML-files, the user can design and run various games for testing agents without adjusting it to the game. The framework has been built with a focus of statistical forward planning (SFP) agents. For this purpose, agents can access and modify game states and use the forward model to simulate the game. Thanks to the ability to configure a wide range of games and access to the forward model, Stratega is perfectly suited for researching general game playing in complex games. 
Type Of Technology Software 
Year Produced 2021 
Impact This software (which is still in development) has been used by postgraduate students (MSc and PhD) for their research in AI & Games. 
URL https://github.com/GAIGResearch/Stratega
 
Description Abstract Forward Models and Strategy Games 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact An invited talk for the (French) Games & AI Day. This day was organized at the initiative of the French Artificial Intelligence Association (AFIA) and the Artificial Intelligence Research Group of the CNRS (GDR IA). The goal of this day was to bring together academic and industrial communities on the theme of AI in games, through two invited presentations, a session of short presentations of ongoing research in the field, and a round table bringing together all the participants. Thus, the day is aimed at young researchers as well as more advanced researchers and industrialists.

Title and abstract of the talk I gave below:

Title: Abstract Forward Models and Strategy Games
Abstract: This talk presents a current research project funded by the UK Research council that aims to investigate how modern Statistical Forward Planning (SFP) algorithms can be used in complex games. SFP techniques, such as Monte Carlo Tree Search (MCTS) or Rolling Horizon Evolutionary Algorithms (RHEA), have recently achieved remarkable performance in games research, and this project addresses the main reasons behind the small uptake of SFP methods in the games industry. This talk will cover our initial work in abstracting forward models, showing how action and state spaces can be reduced for effective decision making. We will also describe our new platform for general strategy games (Stratega), which allows to create a wide variety of turn-based and real-time strategy games using a common API for agent development.
Year(s) Of Engagement Activity 2021
URL https://pfia2021.fr/journees/jeux/#prgfr
 
Description Abstract Forward Models for Modern Games 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Invited research talk given to the University of Malta on the project overview and work done so far and planned. Presentation of our Stratega framework and the main research questions we are aiming to address with it. The talk was attended by different postgraduate students and academic staff from the University of Malta, mostly from the Institute of Digital Games.
Year(s) Of Engagement Activity 2020
 
Description Abstract Forward Models for Modern Games Project Meetings 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Meeting with project partners to discuss the progress in the project. The discussions are useful to influence the decisions on what to work next, as well as to help us shape our research to maximize impact and the application of our techniques in the industry (game companies).

These are regular meetings that happen approximately every 6 months during the length of the project.
Year(s) Of Engagement Activity 2020
 
Description General Strategy Games Framework 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact A talk during the 2020 EECS Research Open Week at QMUL. This was a series of 10 spotlight talks (3 minutes each) about research done in our group, aimed at industry contacts and prospective (MSc, PhD) students.
Year(s) Of Engagement Activity 2020
 
Description IEEE CoG 2021 Tutorial: Stratega: a general strategy games framework 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact This was a 1h tutorial accepted and presented at the IEEE Conference on Games 2021 (full program here, page 12: https://ieee-cog.org/2021/assets/full-program.pdf).
In this tutorial, we presented the software developed during this project to an audience of about 20 attendees to the conference interested in Artificial Intelligence in Strategy Games. It was a very practical tutorial were attendees learnt about how to use the software for their own research. As a result, some of these attendees joined our project Discord channel to be kept up to date with the developments of our framework and ask questions about how to use it.
Year(s) Of Engagement Activity 2021
 
Description Stratega - Abstract Forward Models for Modern Games 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Invited research talk given to the Southern University of Science and Technology (Shenzhen, China) on the project overview and research performed so far. Presentation of our Stratega framework and the main research questions we are aiming to address with it, including the tutorial and competition accepted for IEEE CoG The talk was attended by different postgraduate students and academic staff from the Game AI group at the Southern University of Science and Technology.
Year(s) Of Engagement Activity 2021