825all that really matt ers is the player’s perception of what is going on. A classic
example comes from the game Halo. When Bungie fi rst implemented their AI
system, they included a simple rule that stated that the small “grunt” aliens
would all run away when their leader had died. In play test aft er play test,
no one realized that this was why the litt le guys were running away. Even af-
ter the Bungie team had made various adjustments to the animations and AI
behaviors in the game, still no one got the connection. Finally, the developers
resorted to having one of the grunts say, “Leader dead! Run away!” This just
goes to show that all the AI logic in the world doesn’t amount to anything if
the player doesn’t perceive the meaning behind it.
AI programming is a rich topic, and we certainly have not done it justice
in this book. For more information, see [16], [6] Section 3, [7] Section 3, and
[40] Section 3.
15.2.4. Other Gameplay Systems
Clearly there’s a lot more to a game than just player mechanics, cameras, and
AI. Some games have drivable vehicles, implement specialized types of weap-
onry, allow the player to destroy the environment with the help of a dynam-
ic physics simulation, let the player create his or her own characters, build
custom levels, require the player to solve puzzles, or... Of course, the list of
genre- and game-specifi c features, and all of the specialized soft ware systems
that implement them, could go on forever. Gameplay systems are as rich and
varied as games are. Perhaps this is where your next journey as a game pro-
grammer will begin!
15.2. Gameplay Systems