Reactor (Halo Online map)

From Halopedia, the Halo wiki

This article contains information about a non-canonical subject that, while official, is not part of the established Halo universe.
HO Reactor Overview.png
Map overview


Halo Online

Map file name (?):


Lore information


Lethbridge Industrial reactor site

Gameplay overview


Grassland and Mountains

Recommended gametype(s):

Team Slayer

Being constructed just prior to the Invasion, its builders had to evacuate before it was completed.

Reactor is a Halo Online multiplayer map and one of five known maps to be exclusive to the game.

Universe and lore[edit]

Reactor is set on an unknown UEG colony world. At some point, the world was settled by Lethbridge Industrial, who began constructing a reactor. Ultimately, the planet was invaded by an unknown entity and the site had to be evacuated prior to its completion. The presence of the Charon-class light frigate UNSC Aegis Fate and several D77H-TCI Pelicans and AV-14 Hornets can be seen in the sky above the site. Due to Halo Online's cancellation, the map is considered non-canon.


Reactor is a symmetrical map designed for Big Team Battle modes, with an emphasis on Warthog gameplay. The map has a symmetrical C-shaped layout, with flat grasslands occupying most of the experior space making for long sightlines and vehicular battlegrounds. The middle of the map is composed of the eponymous reactor building, a dome-shaped circular structure with an open core and several exits out into the surrounding grassy area. Each end of the map's C-shape houses a base for either team, with each base a mirror of the one on the other side. Each base features two levels, with the top level connecting to the reactor building via a bridge.[1][2]

Each base houses a singular Warthog and Mongoose, with a building in the centre of the valley housing a neutral Rocket Launcher and Ghost spawn. The middle reactor houses a Sniper Rifle in its upper walkway and an Overshield in the air above the middle reactor rods. To reach the overshield, players must wait until the rods rise into the air, making the shield accessible.[1][2]

Production notes[edit]

Reactor is an original map created for Halo Online. Alongside Edge, it is one of two original maps developed and released for the game that were not remakes of other Halo series maps. Several other cut maps were developed including one known as Sky bridge, though never made it into a playable build of the game. Alongside Sky bridge and Lockout, the map was released as part of the July 2023 content update for Halo: The Master Chief Collection, included in the Halo 3 Editing Kit as raw tag data for modders to use.[3]