The Multiplayer Halo 3 Experience

Like most multiplayer Xbox 360 titles, Halo 3 will use a customised version of True Skill ranking system for its online matchmaking facilities. Halo 3's matchmaking system will be based on two different ranks, skill and experience. Skill will simply be the True Skill rank of the player in a given playlist, and experience identified by a Military rank; e.g. a player with a designation of a '"General" will have played for longer time than someone who is a "recuit". This is in order to make the system more fair and to reflect the effect of experience on players' profiles.[8]
The interface for matchmaking from Halo 2 will be completely revamped. Call signs (consisting of one letter and two numbers) will be used instead of small HUD emblems to identify allies in games. In addition to the customization of call signs, players can now choose three different colors (as opposed to two in Halo 2) for their armour in multiplayer (primary, secondary and detail), as well as three for their multiplayer emblem.[9]
Bungie also stated that they have redesigned the UI (user interface) from Halo 2, apparently making it easier to generate a custom game in Halo 3 multiplayer. Hosts will now be able to "advertise" their custom games via Xbox Live Public; making it easier to find a multiplayer match to a player's taste without having to link up with friends.[8]
In the November 11, 2006 Bungie Weekly Update, it was stated that due to a "significant chunk" of Halo 2 players being female, there might be an option to have a female voice for the Spartan character in multiplayer.
A new feature dubbed the "A-hole button" will be used to mute players in the game.[10] People sifting through the code of the Halo 3 beta have found that the strength of the effect of gravity is customizable as one of the game settings in creating custom games.[11]
There will also be a greater number of medal announcements in multiplayer, including several "Easter egg" medals that will be awarded for very unusual events.