Blocking
In The King of Fighters XIII, blocking works the same way as you would expect in any traditional fighting game. Holding back while your opponent is attacking will block high and middle attacks but not low attacks, and holding down-back while your opponent is attacking will block low and middle attacks.
If you block an attack, you will enter a period of 'blockstun', during which you can't do anything except alternate between standing block and crouching block or execute a Guard Cancel Roll or a Guard Cancel Blowback. The length of blockstun depends on the attack; it's short for light attacks, longer for heavy attacks and special attacks, and the longest for Blowback (CD) attacks. While you are in blockstun, you cannot be thrown.