Procedural generation of non-player characters in massively multiplayer online strategy games
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This paper presents a coevolutionary framework for procedural generation of NPCs in MMORTS games. In this context, players need to defeat environmental troops in battle to gather resources and achieve their goals. The benchmarked game has several balance problems related to these battle activities, mostly caused by the handcraft design of complex game content. To solve this problem, the algorithm takes player modeled heroes as input and returns a solution evolved to win. By this way, the players need to think better in a new way to conquer the victory, adding new levels of challenge, keeping the game enjoyable. We present a new mathematical model to evaluate the solutions, based only on the number of soldiers on the input and output, making it easy to extend to other contexts. The results show it is possible to procedurally generate thousands of new efficient and fair builds, without violating the game rules. Moreover, our analysis of the results was able to identify unbalanced characteristics in the game design and we suggested simple way to fix it.
KeywordsProcedural content generation Evolutionary algorithm Coevolution Massive multiplayer online (MMO) game Real-time strategy (RTS) game Video games
The authors would like to thank to: Prof. Julian Togelius, for sharing his experience during the development of this paper. This study was funded by the following Brazilian agencies: State of Minas Gerais Research Foundation—FAPEMIG; Coordination for the Improvement of Higher Level Personnel—CAPES; National Council of Scientific and Technological Development—CNPq (Grants 30506/2010-2, 312276/2013-3).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- Crawford G, Gosling VK, Light B (2013) Gamers: the social and cultural significance of online games, Routledge advances in sociology, vol 56. Routledge, LondonGoogle Scholar
- Ferreira L, Toledo C (2014) A search-based approach for generating angry birds levels. In: 2014 IEEE conference on computational intelligence and games (CIG), IEEE, IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, Dortmund, Germany, 26–29 Aug 2014Google Scholar
- Goldberg DE (1989) Genetic algorithms in search, optimization, and machine learning. Addison-Wesley Professional, Reading, MAGoogle Scholar
- Heaton J (2008) Introduction to neural networks with Java. Heaton Research, Inc. http://www.heatonresearch.com/encog
- Jansen T (2013) Analyzing evolutionary algorithms: the computer science perspective. Natural computing series. Springer, Berlin. doi: 10.1007/978-3-642-17339-4, http://link.springer.com/book/10.1007%2F978-3-642-17339-4
- Karaboga DD (2005) An idea based on honey bee swarm for numerical optimization. Erciyes University, Engineering Faculty, Computer Engineering Department, Tech. repGoogle Scholar
- Kennedy J, Eberhart R (1995) Particle swarm optimization. In: IEEE international conference on neural networks, 1995., IEEE, Perth, WA, vol 4, pp 1942–1948. doi: 10.1109/ICNN.1995.488968, http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=488968
- Luke S (2009) Essentials of metaheuristics: a set of undergraduate lecture notes. George Mason University, Department of Computer ScienceGoogle Scholar
- Mahlmann T, Togelius J, Yannakakis G (2012) Evolving card sets towards balancing dominion. In: Evolutionary computation (CEC), 2012 IEEE congress on, pp 1–8. doi: 10.1109/CEC.2012.6256441
- Ontanon S, Synnaeve G, Uriarte A, Richoux F (2013) A survey of real-time strategy game ai research and competition in starcraft. Computational intelligence and AI in games, IEEE transactions on 5(4):293–311. doi: 10.1109/TCIAIG.2013.2286295, http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6637024
- Ruela AS, Guimarães FG (2012) Evolving battle formations in massively multiplayer online strategy games. In: SBC—Proceedings of the Brazilian symposium on games and digital entertainment—SBGames 2012, Brasília-DF-Brazil, pp 49–55Google Scholar
- Ruela AS, Guimarães FG (2014) Coevolutionary procedural generation of battle formations in massively multiplayer online strategy games. In: 2014 Brazilian symposium on computer games and digital entertainment (SBGAMES), pp 89–98. doi: 10.1109/SBGAMES.2014.37
- Senior T (2010) Computer program finds devastating starcraft 2 build orders. http://www.pcgamer.com/2010/11/02/computer-program-finds-devastating-starcraft-2-build-orders/
- Shaker N, Togelius J, Yannakakis G, Weber B, Shimizu T, Hashiyama T, Sorenson N, Pasquier P, Mawhorter P, Takahashi G, Smith G, Baumgarten R (2011) The 2010 mario AI championship: level generation track. IEEE Trans Comput Intell AI Games 3:332–347. doi: 10.1109/TCIAIG.2011.2166267 CrossRefGoogle Scholar
- Shaker N, Togelius J, Nelson MJ (2014) Procedural content generation in games: a textbook and an overview of current research. Springer, BerlinGoogle Scholar
- Smith G (2014) Understanding procedural content generation: a design-centric analysis of the role of pcg in games. In: Proceedings of the SIGCHI conference on human factors in computing systems, ACM, New York, NY, USA, CHI ’14, pp 917–926. doi: 10.1145/2556288.2557341
- SuperData Research I (2014) Free-to-play online games market. https://www.superdataresearch.com/market-data/online-games-research/
- Togelius J, Shaker N, Nelson MJ (2014) Introduction. In: Togelius J, Nelson MJ, Shaker N (eds) Procedural content generation in games, A textbook and an overview of current research. Springer, BerlinGoogle Scholar
- Tozour P, Champandard AJ (2012) Making designers obsolete? evolution in game design. Open interview, http://aigamedev.com/open/interview/evolution-in-cityconquest/
- Trepte S, Reinecke L, Juechems K (2012) The social side of gaming: how playing online computer games creates online and offline social support. Comput Hum Behav 28(3):832–839. doi: 10.1016/j.chb.2011.12.003, http://www.sciencedirect.com/science/article/pii/S0747563211002706
- Yannakakis GN, Hallam J, Lund HH (2006) Comparative fun analysis in the innovative playware game platform. In: Proceedings of the 1st world conference for fun and games. Preston, England, pp 64–70Google Scholar