Guillotine is a one-hit KO move, as with all one-hit KO moves it is very inaccurate. Additionally, Pokémon with the Sturdy Ability and Ghost-Types are immune to this attack, unless the Scrappy Ability is in use or another Pokémon used a move that can allow a Ghost-Type to get hit with a Normal-Type attack, such as Foresight or Odor Sleuth.
Accuracy is not calculated the same way as other moves. To calculate Accuracy, let's assume that a Level 78 Haxorus is using this move on a Level 37 Emboar. Subtract Emboar's level, 37, from Haxorus's level, 78, then add 30 to it. 78-37=41+30=71, therefore, Guillotine's accuracy would be 71.
Pokémon that Learn this Move via Level-Up
Pokémon that Learn this Move via Breeding