The balance of weapons changes in this version with three kinds of arms available. These include a special type of grenade that is most effective in crunch situations. The judicious use of weaponry may decide the fate of the player. An added feature of these games is what is called "dual wielding" where the player can use grenades and melee simultaneously combining the firepower of the two weapons.



In addition to this, all weapons featured in previous editions of the game return to Halo 3 with various augmentations. All weapons used by the player are shown on the screen unlike previous parts and additional support weapons are introduced that are cumbersome and tough to carry about.

These weapons carry far more power than the normal weapons and include turret machine guns and things called flamethrowers. The use of these weapons drastically reduces the player's combating skills and movement; but increases his power and shooting range.

A very special addition to this version was a group of utilizable items called Equipments. They have a wide range of functions. While some such as Bubble Shield and Regenerator can be used in defensive operations, others such as the Power Drainer and Tripmine can actually cause mortal damage and death. The player can use only one of these utility products at a time.

The Ark is the mother ring world in the Halo universe. It has the power to control all the other Haloes and is also known as Installation 00. It is often dubbed the controlling station of the Halo network. The Ark first received a mention in the video game series towards the climax of the second version and was the site of most of the action in Halo 3.

The opening to the Ark was situated in the futuristic planet Earth in the continent of Africa. It was located between Mount Kilimanjaro and the city of New Mombassa. On opening it develops a massive portal which takes passengers to Ark. The Ark is petal-shaped and immense in diameter located a few light years beyond the Milky Way galactic sphere. Guilty Spark also mentions that it is 262,144 light years away from the core of the galaxy, the higher range of the network of Halo is measured in light years to be around 210,000.

The final half of Halo:3 primarily locates itself in the Ark where it is also comprehended that the Ark has an inherent capability of producing Halos and also initiated the reconstruction of the destroyed Installation 04. However, it suffers heavy damage when the Halo under construction is fired before being fully developed.

The Ark is also seen to be a storehouse of valuable information about its creators, the mysterious extraterrestrial race known as the Forerunners. In three of the levels that take place in the Ark, terminals located in remote areas contain databanks which reveal the fate of the Forerunners and the spearheads of the fight against the Flood.