Cheap AI

In M.U.G.E.N, Cheap AI refers to a character whose Artificial Intelligence (AI), custom made or patched, enables it to vastly outperform any human using that character. As a result, the AI may be able to exploit the moves of a character to an extent that it can generate seemingly impossble tactics and combos, often resulting in massive damage, pressure or even infinite attacks.

Note that Cheap Characters and Cheap AI are distinct, but can overlap - a cheap character can heave cheap AI that allows it to exploit its cheap moves to the best of its ability.

Background
Before the days of M.U.G.E.N 1.0 (and even in this day to some extent), the built-in AI of M.U.G.E.N was not very good at making characters function well under computer control. As such, there was an impetus to create custom AI for characters.

Even now, most custom AI is built using an AI trigger variable and commands that are impossible for humans to do. Most AI simply puts the character into a certain state when certain conditions are met, allowing for dynamic behavior based on opponent tactics, However, it is exactly because of this lack of human limitations that Cheap AI can result.

Perfect Combos
Characters with this type of Cheap AI tend to be able to land one move and from there, perfectly execute a series of moves with superhuman timing to deal a powerful combo. When a human attempts to do the same combo, it is found that the links are too tight for the combo to be continued by a human.

For example, UM-Krizalid-2K1 will attempt to land Desperate Moment all the time. If it connects, he will proceed to perform a series of uppercuts and grabs that culminate in a super available to him at his power level.

Perfect Response
Characters with this type of Cheap AI also have superhuman reflexes - but for the purposes of being able to counter any move that the player uses with an appropriate move that will cleanly beat it. A huan would not be able to deploy the move in time every time as a counter.

Occassionally, they can even circumvent charging time on charge specials by ging directly into the attack state. Since charge specials are usually more powerful that regular motion specials in compensation for the charge time, this can be an issue.

For example, Yukino Ozawa's AI will immediately throw when within range and counter any jump with a uppercut boasting a ReversalDef - even if the attack has only come out for one frame.

Perfect Pressure
The final kind of Cheap AI has the ability to accurately break any defense by sheer precision, allowing it to slip in high and low attacks far beyond a human's ability to read and response to pressure and mixups, allowing a free combo any time.

One of the most notorious examples is Kusanagi-KOFM. His AI tends to read the opponent's block, run in at very high speed and immediately execute the combo that will go through.