A.I. System in Arcade Games

The first arcade games were built on discrete logic
and were strictly based on competition between the
players. Therefore, there wasn't any A.I. system.

Heuristic algorithms have been used in the arcade
games. The common method of controlling an NPC in the
game was by scripting.

'Path finding' is another common A.I. system that has
been used in the real time strategy games. 'Path
finding' works by calculating how to get an NPC from
one place to another after considering the terrain and
obstacles.

Games like Quake and Pursuit based all the enemy
actions on particular stored patterns. The space
invaders further refined this movement, by adding
in-game events which were dependent on the hash
functions.

This resulted in more varied and complex enemy
movements.

Pac-Man incorporated this technology, at the same time
jazzing it up by providing different personalities for
each ghosts.

Although the ghost movements in Pac-Man felt random,
it was a cleverly scripted and well disguised action.

The 1990's saw the emergence of finite state machines.
The arcade racing games were powered by a 'rubber
banding' A.I. system.

If the computer controlled the opponents "fall
behind", they received a superb boost allowing them to
catch up.

The system too, works the other way around, enabling
the human players to catch up if they fall behind. The
arcade shooting games should ideally have a large rule
base which is basically the list of NPC options like
attack long range, call for help, flee etc.

The trick lies in using a random factor to choose from
this base factor. This has displayed an enhanced
feeling of intellect and developed the fun factor.