In the sequel to Halo Combat Evolved , Spartan-117, better known as the Master Chief, has returned to Earth, where he is promptly needed: despite all precautions taken, the Covenant have discovered the location of humanity's homeworld and are launching their attack. For some reason, however, their fleet is much smaller than expected. To solve this mystery, the Chief must return to the stars, learning more about the mysterious Halo rings and their constructors.
Meanwhile, the Covenant Elite who commanded the fleet at the Halo construct is blamed for the destruction of the ring and branded a heretic. The High Prophets grant him another chance, however: he is made the Arbiter, a special operative for the Prophets, ordered to carry out impossible missions. He will be dealing with dissent and rebellion among the Covenant - a conflict where he might find himself to be on the wrong side. The player controls both the Chief and the Arbiter in Halo 2 , a first-person shooter with similar gameplay characteristics as the first game. The main gameplay features include a limited number of weapons that can be carried at a time, an energy shield that recharges during firefights, AI-controlled teammates, and sections involving vehicles.
New features in Halo 2 include the ability to double-wield certain weapons, which increases firing rate but reduces accuracy, and the execution of melee attacks or throwing grenades. The human projectile weapons are mostly new additions, including a pistol, shotgun, SMG, battle rifle, sniper rifle, rocket launcher, Brute Shot, Fuel Rod Gun, Carbine, Beam Rifle, and Energy Sword.
All vehicles from the original game return: Warthog jeeps and Scorpion tanks for humans, Banshee fliers, Ghost gliders, Wraith tanks, and Spectres for the Covenant. A new player ability is to board a vehicle while it's in use and either take over or throw a grenade. The multiplayer component of Halo 2 has been greatly expanded. The game supports Xbox Live, split-screen, and system link on the Xbox, and campaign play with two players on split-screen. Competitive game types include Slayer, Team Slayer, Capture the Flag, Assault, Territories, Oddball, and more. Players can choose from Spartan and Covenant Elite skins. The PC version comes with a map editor for customization.