Pitt Fighter is a perk added with the Fallout 3 add-on The Pitt.
The perk grants the player a permanent increase of 3% to both their Radiation and Damage resistances (up to the maximum of 85%).
Obtaining the perk
To obtain this perk, the player must win all of the fights in The Hole, which is part of the quest Unsafe Working Conditions.
Behind the scenes
The image for this perk depicts Vault Boy wearing armor identical to what Blaster wore in the film Mad Max: Beyond Thunderdome.