The dizzy state (also known as “stun” [not to be confused with the “stun” that refers to stiffness] or “faint” to some) occurs when enough attacks land on someone. It is found in most 2D games.
It originally comes from Street Fighter II, where it would depict this by having chicks or stars fly around the dizzy character’s head, just like in kids’ cartoons!
While dizzy, you are defenseless and are completely unable to operate your character. This usually means the opponent gets to use that time for whatever he should so wish, whether to taunt or get a guaranteed combo on you.
You can speed up the recovery process by mashing the buttons and going crazy with the stick to flood the inputs, but usually a human opponent won’t give you enough time, so sometimes it’s best to give up and look for a more strategic opening.
The dizzy state occurs when the accumulated dizzy values reach the character’s limit. The dizzy values are always being recovered slowly, and are usually different for each character.
Normally, you do not have any way to tell for sure what level the dizzy values have reached to, but some games (like SFIII and KOFXI) have a meter for it, allowing players to try for “stun combos”, “100% stun combos”, and death combos utilizing stun.
Some moves perform a guaranteed dizzying, though more commonly there are super special moves that leave the character dizzy in the middle, such as Takuma’s Ryūko Ranbu. Because this dizziness is part of the move’s sequence, it is rarely possible to recover from it.