| ||For an overview of Fat Man models that appear in the Fallout series of games, see Fat Man.|
|The following is based on content from Fallout: The Board Game and has not been confirmed by canon sources.|
Before the player character begins their fight, they must succeed at a Luck test or they will not be able to use any rerolls during the fight. If they succeed, the Fat Man generates one reroll each for having Endurance, Intelligence, and Agility. As a ranged weapon, it allows the player character to attack enemies one space away from them. If the player character successfully kills their opponent, the Fat Man also automatically kills a second enemy that is within one space of the defeated enemy.
The Fat Man can be obtained inside Vault 109, if the player character chooses to break into the Vault armory.