Vision & Light | Game Master Companion 5e

Ability to See. How well you see in a situation depends upon (1) the presence and intensity of light, (2) the presence of obstructions, and (3) the proximity and size of the thing observed.

Light. The amount of light (see sources of light table) in an environment creates three categories of illumination:

Bright light lets most creatures see normally.

Dim light, also called shadows, creates a lightly obscured area.

Darkness creates a heavily obscured area.

Obstructions can interfere with vision (both quality of vision and maximum range).

Patchy fog or moderate foliage creates a lightly obscured area.

Opaque fog or dense foliage creates a heavily obscured area.

You can't see something that has total cover.

Maximum range due to outdoor obstructions.

The distance between viewer and object, and the size of the object, affects vision and level of detail discerned.

If you have darkvision or another special sense, your reliance on light is less or non-existent.