Game Development Reference
In-Depth Information
In an incomplete information game, part of the game state is hidden
from some players.
For example, poker is an incomplete information game because you
can't see other players' cards. In contrast, chess is a complete information
game since both players can see everything on the board.
But this traditional distinction doesn't cover all the ways that decision-
relevant information can be hidden. Even seemingly complete informa-
tion games can have decisions because they hide information in other, less
obvious ways.
Information can be hidden in the future behind chains of complex cause
and effect.
Complete information games reveal their present, but not their pos-
sible futures. We can see what the whole chessboard will look like after we
make one potential move, but we can't see what it will look like three turns
down the line. This information is hidden in the future behind a chain of
interactions, and extracting it requires interesting mental effort.
Information is hidden in players' internal states.
Imagine how much easier chess would be if you could read your op-
ponent's mind, know his planned future moves, the vulnerabilities he has
perceived in your position, and the vulnerabilities he hasn't perceived in
his own. This information is part of the game just as much as the posi-
tions of the pieces on the board, but it's hidden.
The most powerful multiplayer experiences are often about divining
and exploiting internal information like this. Reading or controlling an
adversary's mind is one of the most satisfying forms of victory.
Information can be hidden by speed.
The brain takes time to perceive, process, and use information. This
means that information that has arrived within the last fraction of a second
is effectively hidden from our decision-making process. We don't decide
based on the information we perceive now, but based on the information
we perceived a tenth of a second ago.
