5.9 Vision and Light

Some creatures have darkvision or other extraordinary senses, but most creatures need light to see by. In an area of bright illumination, all characters can see clearly. Creatures can see only dimly into areas that have shadowy illumination. Everything in the area has concealment. This allows creatures in the area to make Stealth checks to hide even if they don’t have cover (see Stealth). In an area with brilliant illumination, creatures can see clearly just like an area with bright illumination. In addition, no shadows exist within an an area of brilliant illumination. This makes many effects from the umbramancy mystic sphere difficult or impossible to use. In areas of total darkness, creatures without darkvision or some other form of supernatural vision are blinded (50% miss chance, -2 Armor and Ref).

5.9.1 Emitting Light

Some items and abilities emit light. Any effect which creates bright or brilliant illumination in an area also creates enough light for shadowy illumination in twice that area.

For example, a simple torch emits bright illumination in a Small (15 ft.) radius. That means it also creates shadowy illumination between 15 feet and 30 feet from the torch in a dark room.

5.9.2 Attacking Unseen Foes

You can make targeted attacks against creatures and objects you cannot see. To do so, you choose a 5-foot square and make the attack against that square. You have a 50% miss chance with the attack. Otherwise, you hit a random valid target in that square with your attack, if one exists.

5.9.3 Concealment

Concealment represents anything which makes it more difficult to see your target, such as shadowy illumination. All targeted attacks against a creature or object with concealment from you have a 20% miss chance. Generally, this means that you roll 1d10, and the attack misses on a 1 or 2. Determining concealment works similarly to determining cover. You must use the same points of origin and target square when determining concealment that you would use to determine cover.

Determining Concealment: There are two things that can cause a creature to be concealed: poor lighting, and intervening obstacles that block sight. Determining concealment from obstacles that block sight works the same way as determining cover (see Cover).

Determining concealment from lighting conditions is simpler, since it ignores lighting conditions between you and the target. If your target square is in lighting that provides concealment, the target has concealment. Otherwise, it does not.