AI in Computer Gaming:AI in Computer Gaming:The first person shooterThe first person shooter

Tyler HulburdTyler Hulburd

Brief HistoryBrief History

• Games that featured a single player mode with enemies started Games that featured a single player mode with enemies started appearing in the 1970s. appearing in the 1970s.

• Enemy movement was based on stored patterns. Enemy movement was based on stored patterns. • The idea was perfected with The idea was perfected with Space InvadersSpace Invaders (1978), sporting an (1978), sporting an

increasing difficulty level, distinct movement patterns, and in-increasing difficulty level, distinct movement patterns, and in-game events dependent on hash functions based on the player's game events dependent on hash functions based on the player's input. input.

• The incorporation of microprocessors would allow more The incorporation of microprocessors would allow more computation and random elements overlaid into movement computation and random elements overlaid into movement patterns.patterns.

• The emergence of new game genres in the 1990s prompted the The emergence of new game genres in the 1990s prompted the use of formal AI tools like finite state machines. use of formal AI tools like finite state machines.

• Later games have used nondeterministic AI methods, ranging Later games have used nondeterministic AI methods, ranging from the first use of neural networks in a videogame in from the first use of neural networks in a videogame in Battlecruiser 3000ADBattlecruiser 3000AD (1996), to the emergent behavior and (1996), to the emergent behavior and evaluation of player actions in games like evaluation of player actions in games like CreaturesCreatures or or Black & Black & WhiteWhite. .

Far Cry (2004)Far Cry (2004)

• Far CryFar Cry exhibited very advanced AI for its exhibited very advanced AI for its time. The enemies would react to the time. The enemies would react to the player's playing style and try to surround player's playing style and try to surround him when possible. They would also use real him when possible. They would also use real life military tactics to try and beat the life military tactics to try and beat the player. The enemies did not have "cheating" player. The enemies did not have "cheating" AI, in the sense that they did not always AI, in the sense that they did not always know exactly where the player is all the know exactly where the player is all the time. They would remember his last known time. They would remember his last known position and work from there. position and work from there.

Half Life 2 (2004)Half Life 2 (2004)

• In In Half Life 2Half Life 2 enemies are more alert to the enemies are more alert to the presence of the player and take cover when presence of the player and take cover when injured. Allies follow the player and help injured. Allies follow the player and help fight against enemies. When engaging fight against enemies. When engaging enemies, instead of always remaining in enemies, instead of always remaining in place until either the target or they place until either the target or they themselves died, allies will disengage when themselves died, allies will disengage when the player moves on. the player moves on. Half-Life 2Half-Life 2 also has also has group commands for ordering allies around. group commands for ordering allies around.

Halo 3 (2007)Halo 3 (2007)

• Uses some new AI approaches such Uses some new AI approaches such as enemies getting scared and as enemies getting scared and fleeing a battle. Also some enemies fleeing a battle. Also some enemies will actively try to commit suicide and will actively try to commit suicide and take the player out at the same time. take the player out at the same time. Enemies could drive vehicles that Enemies could drive vehicles that could also transport other enemies could also transport other enemies (enemy players use teamwork).(enemy players use teamwork).

Things to come:Things to come:

• NPC’s that learn..NPC’s that learn..– As AI in games continues to improve As AI in games continues to improve

npc’s are able to learn from the players npc’s are able to learn from the players behavior and adapt accordingly. For behavior and adapt accordingly. For example, the npc could mimic the example, the npc could mimic the players behavior or choose a different players behavior or choose a different strategy to counter it.strategy to counter it.

Questions?Questions?