Quick Attack cancel

QAC, also known as Quick Attack Cancelling or QuACking, is the ability of Pikachu in SSBB to quick attack into the ground and cancel the lag at the end of the momentum allowing Pikachu to approach very quickly.

The Concept

By aiming the first half of the quick attack down and to a direction against the ground, Pikachu loses all lag from the move. This allows Pikachu to cancel the quick attack into any aerial move outside of down air (called QAC Flash or Quick attack Flash). This is usually used into neutral aerials or down b kills (both vertical and horizontal). Due to the properties of the move, it is possible to "stun" the opponent using the first half of the quick attack and then hit them with another aerial or consistently hit someone's shield. It is also part of many techniques:

• Quick Attack Lock or QAC Lock: By footstooling an opponent and then repeatedly QAC'ing into an opponent, Pikachu can infinite an opponent. It is possible to also QAC lock if an opponent near you misses a tech
• Slope Cancelling: By quick attacking against any slope, Pikachu can cancel the quick attack into any move and gain momentum
• Quick Attack Edgehog: You can quick attack cancel off the ledge and then regrab the ledge with the 2nd half of the quick attack

[1]: The Pikachu Guide, including Quick Attack Cancel and similar techniques