Looting

This proficiency represents a knack for grabbing the best loot in the shortest time. For instance, a cat burglar breaks into a room in a wealthy mansion. He has about two minutes to fill his backpack, so that he can escape before guards are summoned by magical alarms. If his proficiency check succeeds, he is able to recognize and stuff into his pack the most valuable combination of items that is feasible, given his limitations of time and space.

[Complete Thief's Handbook]