The art of combat canceling can be described by some as a necessary exploit for many fighting and action games. While it may seem unfair to others, many top tier players can't live without it.

In a special feature article on Gamasutra, God of War lead combat and systems designer Eric Williams talks all about the mechanics behind action game cancels - the ability to end one animation early and transition it into the beginning of another animation.

Combat canceling first started with the classic roundhouse kick plus Hadouken combo incorporated into Ryu's moves from Street Fighter II. While this was first classified as a "bug" according to the developers, its usefulness to players made them decide to keep the unintentional exploit, and thus began a growing trend in many action games today.

Canceling is divided into two main categories. Perhaps the best way to explain the two types of canceling would be to hear it from Williams himself:

A “Partial Cancel” allows an animation to be canceled at specific windows during the animation. The two most common conditions for a “Partial Cancel” are Pre-hit frame (the animation can be canceled any time before the first frame of the hit) and post-hit frame (the animation can be canceled any time after the last frame of the hit).

A “Complete Cancel” allows an animation to be canceled at any time during the animation. I'm generalizing, and there are special nuances that exist in certain games, but for the most part, these conditions are used 99 percent of the time.