Containment

Containment is a Halo 2 multiplayer map. It was added to Halo 2 in the Bonus Map Pack and released alongside the Halo 2 port as part of Halo: The Master Chief Collection. It is sometimes referred to as the map "That's so big, it won't fit into the Xbox."

Overview
"Part fortress, part laboratory, the Flood Quarantine zone is a prison within a prison. This frozen swathe of tundra lies lifeless and barren, for now..."

This frigid, canyon-enclosed, semi-symmetrical area is likely the result of semi-randomized Forerunner landscape creation. Though the quarantine wall was not part of standard Flood containment protocols, the installation's outbreak and lack of monitor supervision required unique countermeasures. Ancient Forerunner security barriers create a biological airlock— separating this dead and forgotten place from the rest of Halo. The massive gate mechanisms still function, and like metal sentinels they watch over a landscape scoured in millennia past by Flood infection.

It is set in a fault between two snowy cliffs, and there are two massive Forerunner fortresses on either side of the map, acting as bases and also the barricades meant to defend against the Flood.

Topography
It is similar to Coagulation, in the sense that it consists of open, hilly terrain, as well as being a big Snipers map. On each side is an old Forerunner ruin, acting each as a base. Each base, red and blue, has a large gate (resembling a ramp, and functioning as one until opened). The panels that open each are nearby. Once opened, vehicles can enter each base, though. Players can also go around through the caves, or you can jump the ledge without a vehicle to enter the bases on foot. There are two fully functional gate switches and opening gates. There are two Warthogs, two Scorpions, and two Banshees by default spawning. It is ideal for large, system link games or even Xbox Live games, about 6-16 people. Any number less than six players could result in a slow match, as the map is simply so large finding enemies becomes a challenge.

The level also resembles the classic multiplayer level from Halo: Combat Evolved, Sidewinder, being set in the snow and having a blue and red base. However, this map is very different from Sidewinder in its layout, but is not a remake of the map. It was, ironically, originally intended to be a remake of the Halo: Combat Evolved for PC map, Timberland. The map has many similarities to Battle Creek in the first area, as each end has a complex base with many levels, and is set in a valley with alternate base entrances and teleporters, though of course on a far larger scale.

Tactics

 * Though there are normally only two sniper spawns (one at each base), stay hidden. Snipers favor this large, concealing landscape. Competent snipers can make quick work of an advancing group, due to the open nature of the level. There is an assortment of cover around (the variety of rocks sticking up; the small indent on the sides of the bases, etc.), but not enough for you to shoot it out with a foe across the course.
 * Watch for the mines. They are incredibly devastating. Keeping this in mind, they can easily be used, as a deterrent from a Warthog- the opportunities for traps are endless.
 * The giant ramps open on each of the bases. This allows the Scorpion tank access to the inside.
 * In CTF, if you are defending, always post a guard on top of the base. This is important, as you do not want anyone jumping down from behind and stealing the flag.
 * Don't underestimate the network of tunnels running throughout the level. A dislike of would-be snipers and rocket users, you can easily avoid the open space by learning to navigate these tunnels. Each base also has an entrance (on two sides) from this tunnel network- don't forget about it.
 * The turrets are usually a bad decision. It's asking to be sniped or rocketed, and there's also a fair chance that a vehicle will kill you.
 * In CTF, get the Active Camouflage and enter from the base's roof. Remember to take out any guards beforehand.

Production notes
"This map is so big, the Xbox can't even hold it!"

- Paul Russel

Containment was created by designer Steve Cotton and environment artists Paul Russel and Michael Wu over a period of three months. Cotton started intending to remake the Halo: Combat Evolved PC Port's Timberland level, though the bases ended up becoming more intracate with a similarity to those found on Sidewinder, with the overall map layout eventually changing completely. Max Hoberman provided additional oversight on the level to make sure the map didn't get too crazy, and programmer Jason Major was on hand to handle the performance and dynamic elements.

The level originally had what are referred to as "boo bags", described by Wu as "clusters of these boogers all over the level that would explode and harm you". Hoberman ultimately decided they bounced too much and made them static, a decision which upset Cotton and Russel. These "boo bags" eventually turned into the seven energy cores found littering the map in the final game.

Part of Cotton's design goals for the map was to promote interesting vehicle gameplay, with the final level having up to twelve players in vehicles at any one time. In particular, Cotton wanted to incorporate the Scorpion but "hopefully effectively this time". Russel chose the map's theme due to a wish to revisit the Sentinel wall from the campaign.

Easter eggs

 * If you take a sniper rifle and look at the Halo around the level near the sun base (the one with the orange yellow glowing buildings) you will see the face of Chris Carney, one of Bungie's developers, smiling. In the Machinima series "This Spartan Life" one of the players gets an unlock and is trapped playing Halo 2 as the face.
 * Two Marathon symbols are present on the doors at the back of each base.

Glitches

 * If the gate is already open and you approach the switch, it will still display "Press X to open gate".