Blackout

Blackout is the third of the three maps that make up the Legendary Map Pack in Halo 3. It is a remake of the classic Halo 2 map, Lockout.

Instead of a Forerunner facility, this map takes place in the Arctic of Earth, on UNSC Weather Station z/41. The layout is mostly identical to that of Lockout, but includes more grenades and equipment. It is also the only Halo 3 map to take place during the night.

Blackout's code name was Moonlight Sonata during its development due to the level being at midnight. It replaced Purple Reign in the Halo 3 Legendary Map Pack. Purple Reign will be in a later map pack. It has been confirmed that this map takes place at the Arctic and not Antarctica because the Aurora Borealis also known as The Northern Lights can be seen in the sky.

Bungie nearly didn't make the map, because they already had Guardian, which was based on Lockout. The reason they made Blackout was because Lockout was one of the most popular Halo 2 multiplayer maps and was one of the most requested maps for remake.