Blackout

Blackout is a multiplayer map featured in Halo 3 and is a remake of the classic Halo 2 map, Lockout. It is featured as one of the three maps in the Legendary Map Pack that became available on April 15th, 2008.

Rather than a Forerunner facility, like its predecessor, this map takes place in the Arctic. on Weather Station z/41. The layout is almost identical to that of Lockout, but features more grenades and now includes equipment. Most of the jumps, even the crazy ones from Halo 2, are still there. However a number of things have been modified or removed such as one area which was altered to make it more difficult to lock down that part of the map.

Blackout's code name was Moonlight Sonata during its development due to the levels dark nighttime sky. It replaces Purple Reign in the Halo 3 Legendary Map Pack. Purple Reign will be included in a later map pack. Rather than the blue gravity lift that was featured in Lockout, Blackout has a red air shaft, which appears to fit the atmosphere better.

Bungie almost didn't make the map, because they already had Guardian, but with fans still asking for one, they went ahead and made it.

Geometry and Forge
In the most recent ViDoc, multiple forge items from Blackout were revealed. They include stair cases, man-cannons, standard dooring to block doorways, shield doors, and newly edited shipping crates which stay once they are placed on. Another new object is the FX. Using these will change the tint, contrast, brightness, and overall color of the map, and it is recommended to experiment. You may combine them to make cool effects. A full tour of this map can be viewed here. According to 1UP's update, Blackout contains a basket ball hoop and the BR tower is now featured with windows compared to being fully opened. The cartography and common anatomy of the level resembles Lockout in almost every way, shape, or form with little differences.

Trivia

 * Blackout's codename was "Moonlight Sonata" (an allusion to one of Beethoven's works).
 * The lights in the sky are the Aurora Borealis (Northern Lights).
 * This is the only Multiplayer map in Halo 3 so far situated on an Earth locale that is not in Africa.
 * Bungie claims that the model for Blackout was rebuilt because the original model of Lockout was too messy and chaotic to work with.
 * The only weapon spawn point differences is that the spawn points where the Needlers used to be have been replaced by Brute Spikers.
 * The old death defying jumps for Halo 2's Lockout can still be accomplished.
 * Blackout has more Plasma Grenade spawns than Fragmentation Grenade spawns. It is the only map in Halo 3 for which this is the case.
 * There is a basketball hoop (Shown on a Bungie Weekly Update) located in the Barracks building in the right corner.
 * The map is slightly larger than Lockout in some aspects and areas, the Battle Rifle tower is actually larger, the Barracks are smaller, and the Platform next to the Sniper tower is larger.
 * Upon falling off the platform, a splash can be seen after your character lands in the water. On other occasions, if your character lands in the water flat on his/her back or stomach he/she will land and slowly sink downward into the ocean.
 * Getting out of the map is easy, just float down under the platforms and you're there. However, you can't build anything down there because of something called "Map Radiation". If you stay out of the map too long, you will die and the game calls it falling to your death and things placed are automatically deleted.
 * Just like the original Lockout there is a Sniper Rifle in front of a Fusion Coil (In Lockout there were 3 Power Cores instead) and when shot the Rifle will land in almost exactly the same spot as it did in Lockout.
 * The backdrop of this map was once being used as the Bungie.net website's background, but has now been changed.
 * In Lockout, near the Sniper Rifle lies 3 Power Cores (The Forerunner version of Fusion Coils), but in Blackout this there's only one Fusion Coil. The reason may be because in the original Lockout players on the other tower could use the explosives to easily kill a Sniper if one lurks at the position of the Sniper Rifle spawn point. The change decreases the explosive force impacted on players nearby, although, the Sniper Rifle can be blown around or even off the map if the Fusion Coils are set off.
 * The windows throughout the map are identical, including their reflection. The windows were originally made for the Barracks (opposite the lift). The reflection when you look in these windows is a blurry view of the lift area. If you look into the other windows (bottom of sniper tower are easiest to see), you will see the same image.
 * Blackout is a favored map for Team SWAT because of its mix of long and short range combat.
 * The room right behind the sniper spawn cannot be entered.
 * Interstingly this map has been a hotbed for the Ghosts of Halo.
 * Blackout is only Halo 3 map that does not spawn a Brute Shot by default.