Decision Games involve players taking the role of a character and engaging in tough choices that can mean life or death.
Decision Games can be found in the Arcade areas.
The format is loosely based on the third game in the 999 series, Zero Time Dilemma. In this format, players attempt to outwit Zero's Decision Game, since most of the choices would result in death, or something else that'd be painful for the character.
Like Class Trials, every player is given a character document, and that player must try to act as their character would. In some cases, a character may also infact be Zero, or an accomplice.
This format is a lot more story heavy and GM reliant than the others.
An example of a Wild West themed Decision Game.