Game Development Reference
In-Depth Information
the rules but can see everything about the current game-state. A strategy
game without a fog of war system (which makes parts of the map outside
of your unit's field of view impossible to see) has perfect information, but
if the game has a fog of war, then it has imperfect information. Any FPS
game has imperfect information due to the limited field of view (there
are always areas of the game that you cannot see). Alternatively, when we
say a game has complete information, this simply means that all players
know the rules, but not everything about the current game-state.
In video games, designers rarely consider the question of informa-
tion, and may change the type of information available to the player
without realizing it. For instance, a game with scrolling almost certainly
has imperfect information, because things are happening off-screen
Adding a mini-map with enough information may return it to perfect
information status.
Solvability
It's wise to take some time and figure out which kind of information your
game has, because it affects the
solvability
of your game. The first thing
to consider is that
all games are theoretically solvable
—it's just a matter
of how long it takes.
First, what does it mean to solve a game? It essentially means that we
know the “answer� to the game, a strategy that is optimal. Sometimes this
strategy is one that makes the player unbeatable, as happened with
Con-
nect Four
. A mathematician by the name of James D. Allen solved that
game in 1988, and his strategy allows the first player to force a win 100%
of the time. Sometimes solving means forcing a draw (at the worst), as
is the case for tic-tac-toe or Three Men's Morris. We all know this about
tic-tac-toe; playing it with an adult almost surely leads to a draw every
time. This is because we've all solved the game. However, for young chil-
dren, tic-tac-toe can still be an unsolved game.
Games with imperfect information usually cannot be “solved� to
the degree that the perfect information games can be. Since the game-
state at a given point is not known, instead of an absolute solution, you
get an optimal strategy. For instance, the theoretical optimal strategy of
rock-paper-scissors is to play a completely random symbol each time.
Of course, this may not actually be the optimal strategy in a limited con-
text (i.e., in the way the game is normally played), but over a sufficient
number of hands it would win. It may take a higher number of hands to
start producing a better win percentage due to the natural proclivities of
a human opponent.
Some games are partially solved. For instance, chess is not solved but
there are various “solved� (i.e., optimal) starting moves (openings), and
