A Block, not to be confused with a Parry, is a way of preventing damage done to the character using it. In order to block, one must move in the opposite direction of the foe; they should block automatically when attacked.
Blocking can be done standing, crouching, and - in the Street Fighter Alpha series and Marvel vs. Capcom series - in midair. Whether or not an attack is blocked depends on what angle the attack is coming from and which direction the player blocked.
- If one is attacked via crouching attack by the foe, then the player must do a crouching block -- the standing block will not prevent the attack.
- If one is attacked while standing, crouching or standing blocks are fine.
- Overhead attacks can bypass crouching blocks, as they strike high, despite appearing to aim low.
- If one is attacked via aerial means, a standing block must be used -- crouching will not do anything to prevent it (although it could evade the attack).
When blocking a special attack (including more powerful variants such as Super Combos), the blocker will receive Chip Damage. Grab attacks cannot be blocked, but in Street Fighter IV, a "technical" may be performed by attempting to grab a foe who tries to do the same, and cancel out both attempts.
In Street Fighter Alpha 3, all characters have a "Guard Gauge" which limits their ability to continuously block. Certain play modes (V-ism specifically) allow a bigger Guard Gauge. In Classic Mode, however, there is no gauge at all, in addition to the lack of Super Combos.