Precision Mode is a cheat that shortens the timing windows for notes to be hit, making the game feel difficult similar to Guitar Hero II's game engine. Precision Mode can be found in Guitar Hero III: Legends of Rock and Guitar Hero: Aerosmith.
Since this cheat provides a negative effect on the gameplay to provide a better challenge, achievements can still be unlocked and high scores can still be saved while this cheat is enabled.
This cheat and Guitar Hero III's Easy Expert cheat cannot be enabled simultaneously as they have opposite effects.