Different creatures and abilities may use different senses. These senses can determine whether darkness, concealment, noise, scent, or magic blocks perception.

SenseEffect
Normal sensesHuman-standard sight, hearing, and smell or close equivalents.
Night visionSees well in dim, shadowed, or dark conditions.
NethervisionSees into the netherverse, etherverse, or shadowrealm.
UltravisionSees leylines and outlines across all things, sometimes including magically concealed creatures or objects.
Sense magicSees magical fields, similar to a personal reveal magic effect.
Aura senseSees the aura of living things; most undead give off a black aura.
Acute smellNavigates by smell; overwhelming smells can disable or interfere with it.
Chemical senseDetects pheromones or chemical traces such as trails, food, danger, or familiar creatures.
EcholocationUses reflected sound to see or navigate; loud noises or specific frequencies can blind it.
Electro-receptiveDetects electrical fields, including muscle movement; electricity can blind it.
Heat visionDetects heat variation; matching or masking body temperature can defeat it.
Hyper-acute hearingHears distant or soft sounds clearly; loud noises can disable it.