Bayesian Programming and Learning for Multi-Player Video Games ...

effects. In RTS games, there is a lot of strategy and tactics that have to be infered from
partial information.
• Inductive reasoning: the capacity for abstraction, generalization, going from simple observations
to a more general concept. A simple example of generalization is: [Q of the sample
has attribute A] ⇒ [Q of the population has attribute A]. In all games, it is important
to be able to induce the overall strategy of the opponent’s from action-level observations.
In games which benefit from a really abstract level of reasoning (Chess, Go, RTS), it is
particularly important as it allows to reduce the complexity of the problem at hand, by
abstracting it and reasoning in abstractions.
• Decision-making: the capacity to take decisions, possibly under uncertainty and stress.
Selecting a course of actions to follow while not being sure of their effect is a key ability
in games, particularly in (very) partial information games as Poker (in which randomness
even adds to the problem) and RTS games. It is important in Chess and Go too as
reasoning about abstractions (as for RTS) brings some uncertainty about the effects of
moves too.
• Knowledge: we distinguish two kinds of knowledge in games: knowledge of the game and
knowledge of particular situations (“knowledge of the map”). The duality doesn’t exist in
Chess, Go and Poker. However, for instance for racing games, knowledge of the map is
most often more important than knowledge of the game (game mechanics and game rules,
which are quite simple). In FPS games, this is true too as good shortcuts, ambushes and
efficient movements comes from good knowledge of the map, while rules are quite simple.
In RPG, rules (skills and spells effects, durations, costs...) are much more complex to
grasp, so knowlege of the game is perhaps more important. Finally, for RTS games, there
are some map-specific strategies and tactics, but the game rules and overall strategies are
also already complex to grasp. The longer are the rules of the game to explain, the higher
the complexity of the game and thus the benefit from knowledge of the game itself.
• Psychology: the capacity to know the opponent’s move by knowing them, their style,
and reasoning about what they think. It is particularly important in competitive games
for which there are multiple possible styles, which is not really the case for Chess, Go
and racing games. As players have multiple possible valid moves, reasoning about their
decision-making process and effectively predicting what they will do is what differentiate
good players from the best ones.
Finally, we made a quick survey among gamers and regrouped the 108 answers in table 2.9
page 39. The goal was a to get a grasp on which skills are correlated to which gameplays. The
questions that we asked can be found in Appendix A.2. Answers mostly come from good to
highly competitive (on a national level) amateurs. To test the “psychology” component of the
gameplay, we asked players if they could predict the next moves of their opponents by knowing
them personally or by knowing what the best moves (best play) was for them. As expected,
Poker has the strongest psychological dimension, followed by FPS and RTS games.
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