Can somebody tell me what A.I systems are most commonly used these days and why? Also can somebody answer the same question regarding soccer titles? Could all answers be in laymans terms please

AI is very game specific, and in games there may be different parts to it, for example, a pathfinder is often used as a part of it to find the best path between 2 points and another part will decide which points to go to. But leaving that vagueness aside, here is the answer I hope you want:

A Finite State Machine (FSM) is probably the most popular in games, basically, the computer''s mind is in one of a fixed number of states, for example, in a first person shooter, a monster could either be:

Guarding
Patrolling
Following
Attacking
Fleeing

While in one of those states, the computer will behave differently, so when the computer is in the Guarding state, it will stand still, looking for any enemies. If it does see one, it will go into the attacking state, where it will fire at the player. If the player runs away, it will go into the following state, and chase after the player. Then if the player hurts the monster a lot, it may go into the fleeing state and run away from the player.
The reasons it is very popular are:

Simplicity: The concept is quite simple to work with, and therefore will not take too long to make.

Predictable: Although this seems bad, (and in many ways it is) it is sometimes a benefit, say the level designer wants a monster to guard a bridge because there is to be a large showdown there, if the monster decides it would be better to walk off, then the designer doesn''t have control and will probably get frustrated.

The downfalls:

Predictable: It will behave exactly the same way every time it is played, so the player will be one step ahead.

Doesn''t learn: Since there are always small quirks with AI systems, some allow themselves to learn from past experiences, a simple example is in some fighting games, the computer will remember what moves the player uses most ofter and be quicker to respond to those moves.

Other AI types to look into:
Genetic Programming, Fuzzy Logic, Neural Networks, and that''s all I can think of right now

hth

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