Halo 2 is a shooter game. Players primarily experience gameplay from a first-person perspective, with the viewpoint shifting to third-person for vehicle segments.[4] Players use a combination of human and Covenant weaponry and vehicles to progress through the game's levels. Certain weapons can be dual-wielded, allowing the player to trade accuracy, the use of grenades, and melee attacks for raw firepower.[5] The player can carry two weapons at a time (or three if dual-wielding, with one weapon remaining holstered), with each weapon having strengths in different combat situations. Most Covenant weapons, for example, eschew disposable ammo magazines for a contained battery, which cannot be replaced once depleted. However, these weapons overheat if fired continuously.[5] Human weapons are less effective at penetrating shields and require reloading ammunition, but cannot overheat due to prolonged fire. Players can hijack enemy vehicles and quickly assume control of them. The player is equipped with a damage-absorbing shield that regenerates when not taking fire; their health bar is not visible.[5]
The game's "Campaign" mode offers options for both single-player and cooperative multiplayer participation. In campaign mode, the player must complete a series of levels that encompass Halo 2's storyline. These levels alternate between the Master Chief and a Covenant Elite called the Arbiter, who occupy diametrically opposed roles in the story's conflict. Aside from variations in storyline, the Arbiter differs from Master Chief only in that his armor lacks a flashlight; instead, it is equipped with a short duration rechargeable form of active camouflage that disappears when the player attacks or takes damage.[6] There are four difficulty levels in campaign mode: Easy, Normal, Heroic, and Legendary. An increase in difficulty will result in an increase in the number, rank, health, damage, and accuracy of enemies; a reduction of duration and an increase in recharge time for the Arbiter's active camouflage; a decrease in the player's health and shields; and occasional changes in dialogue. Enemy and friendly artificial intelligence is dynamic, and replaying the same encounters repeatedly will demonstrate different behavior.[4]
Multiplayer
Like Halo: Combat Evolved, the Xbox version of Halo 2 features a multiplayer system that allows players to compete with each other in split-screen and system link modes; in addition, it added support for online multiplayer via Xbox Live.[5] The Xbox Live multiplayer and downloadable content features of the Xbox version of Halo 2 were supported until the discontinuation of the service in April 2010,[7] with the final multiplayer session concluding May 10, almost a month after the service was officially terminated.[8] Multiplayer for the PC version of the game used Games for Windows – Live.[9] PC multiplayer servers were taken offline in June 2013.[10][11]
Instead of implementing multiplayer by having players manually join lobbies, as was common in games at the time, Halo 2 used matchmaking. Players chose the general type of match they want to play, and the game selected the map and gametype and automatically found other players.[12] This "playlist" system automated the process of finding matches to keep a steady flow of games available at all times, and combined a skill-ranking system on top.[13]
