Gephyrophobia

Gephyrophobia is a multiplayer map exclusive only to Halo PC. The map is very similar to the Halo: Combat Evolved campaign level Assault on the Control Room. It consists of a large two-level metal bridge expanding over a misty pit. It was reimagined as Narrows for Halo 3.

Overview
This map consists of three levels of play area: the bottom floor of the bridge, the upper floor of the bridge and the two ledges on the side of the canyon overlooking the bridge (connected by teleporters which is accessible in each base). In the middle of this map is the main support tower for the bridge. By default, the map provides an array of Ghosts, Warthogss and Banshees on each of these levels to maneuver around the map. Health packs are plentiful, placed strategically around the map to replenish player's health as they fight their way to the opposing team's base.

The level emphasizes control of long-range and power weapons. For example, sniping and the use of rocket launcher and fuel rods are quite common to repel players and eliminate enemy vehicles. Snipers often make use of the ledges to navigate around and pick their targets. Shotguns are often used in close-quarters in an engagement inside a base.

Popular gametypes played in this map are Capture the Flag, Slayer and Race.

Tactics

 * A common tactic is to rush for the sniper rifles as soon as the match starts, and focus on the ledges to remove opposing snipers. Once so, it would allow the team to advance safely to the opposing team's base (for CTF) or it would provide a good area of control for the sniper's team to dominate a match.
 * Another common tactic in CTF is to rush for the Ghost on the lower level of the bridge, infiltrate the opposing team's base with the Ghost, take the flag and run off with the Ghost to score a point. It is best to do this when the base has little to no resistance. If there is resistance, have the rest of the team to distract players out of their base.
 * In Race gametype, it is best to take a Warthog over a Ghost for reasons that a Warthog can carry up to three players whereas a Ghost is limited to one. Scoring a lap in a fully-occupied Warthog would net the team three points whereas a Ghost-driven player would only score one point. Additionally, a Warthog with a gunner can quickly remove Ghost-driven player easily.
 * It is possible to land a Banshee on the top of the center support tower, which is an excellent sniping location, and has a medkit situated in the center. However, should someone knock off the Banshee while you are on the tower, you will be trapped, unless the shield setting is on 400% then you could climb down the beams connected to the tower and jump to the lower slope connecting the lower bridge to the upper level. Note that it is important to crouch before hitting the slope itself or you will not surive the fall.

Trivia

 * Gephyrophobia means "fear of bridges".
 * Gephyrophobia is far larger in size than its successor, Narrows, although it shares many similarities.
 * The energy beams that reside in and out of the bridge, though seemingly just light, are solid and can be climbed.When shot these beams emit purple electricity.