Multiplayer - Designing Games - page 178

As with the castle battle, Thag's and Blarg's choices depend on the
choice of the other. One caveman's decision process isn't about stags and
hares as much as it is about predicting the other caveman's decision pro-
cess. Each must think about not just how hungry he is, but how hungry his
counterpart is, and how hungry his counterpart thinks he is, and so on.
Recall the mental layer of skill reinvention—the pokerlike psychologi-
cal mind game where each player tries to predict and manipulate the mind
of the others. This is game-theoretic thinking. When there is someone
else actively thinking back at you, the game becomes about more than
mechanics. It becomes a lens through which two minds interact, each
attempting to envelop the other inside its own mental model. And for com-
petitive players, there's no victory sweeter than that.
games anD stRategy inteRaCtions
Before we go on, I'd like to clarify a definition.
Game theorists use the word game differently than game designers.
To them, a game is a specific interaction between strategies. For example,
a single round of rock-paper-scissors is considered a game in game theory.
But in game design, a game is an entire system of mechanics, not a single
decision point.
To emphasize the difference, I'll be calling game theory games strat-
egy interactions from here on. The games we design generate many strat-
egy interactions during the course of play, each of which can be examined
individually using game theory.