

how close you need to be to a hostile creature or character for them to show up on the compass.

It also determines the detection radius, i.e. Perception determines the initial level of Explosives, Lockpick and Energy Weapons. A combination of Perception and the Traps skill is used to detect traps placed on the ground. Perception determines Sequence, ranged combat distance modifiers, the starting level of First Aid, Doctor, Lockpick, Pilot, and Traps and the distance at which sneaking characters get detected.
