Floodlight

Floodlights, or rat lights, are bright, intense lights used by Dunwall authorities to deter the rats that have infested and infected the city. Like all other technologies, they are powered by whale oil, and several mechanisms use floodlights, such as watchtowers and tallboys.

Floodlights can impede stealth, as Corvo Attano is more easily spotted while in their glare.

Trivia

 * Floodlights are manufactured using a special type of crystal. Deposits of the valuable mineral were recently discovered on land belonging to the Boyle family.
 * They are also used on the drawbridge section of Kaldwin's Bridge to watch for any boats passing through at night and are required to be disabled for Samuel Beechworth to reach Anton Sokolov's Safehouse at North End during the mission The Royal Physician.
 * Floodlights in Dishonored 2 and Dishonored: Death of the Outsider are manufactured by Rosewine Industries and Whillock.