Night vision/doc

• You're able to see an additional tile farther in dark conditions (night, underground, etc). Stacks with full moons and other sources of ambient light.
• +2 squares to sight radius in darkness.
• In 0.D (Danny) lighting was changed, so this stacks with less sources of light. And it automatically turns off in strong light.
• Cannot be used to read.
• This is generally considered a great starting trait for new players. Most new players don't have the experience to fight or loot in the day safely, so night raiding is usually recommended to let them feel out the game. Night vision's boost is recommended so they can see threats early, as well as loot better during the night.