When one plays through a video game (usually an RPG) with no equipped armor or other stat boosters. Makes for an extremely challenging and interesting gaming experience (especially because your character often will be naked without equipped armor/items).
Gamer 1: Have you tried out Dragon Age: Origins
Gamer 2: I got it the day it came out! I've already completed a naked run
Gamer 1: Really?!
Gamer 2: Yeah, it was VERY challenging, and it was funny to watch my character run around in his skivvies
Gamer 1: Sounds awesome! I might have to play in my briefs
along with my character.
Gamer 2: ...