Perception is used for both passive observation and focused detection; whether hunting for something specific, a general scan of an area, or simple awareness of their surroundings. Specific conditions – darkness, for example – may affect the Difficulty Grade of the skill roll depending on the primary senses being utilized. Strong scents might make an olfactory Perception roll Easy rather than Standard, whereas trying to eavesdrop on a conversation in a crowded and noisy tavern would make the roll Hard.