Zui Quan, or Drunken Fist

Drunken Fist (called Zui Quan in China) is a kung fu style where a person pretends to be drunk, and fools their opponent into going all out against them, and then the "drunk" person executes some devastating moves. Ronin was a master at this art of fighting.

The general purpose of the technique is to make the opponent underestimate the user, making the fight easier for the user to finish.