Double EXP Weekend

Every weekend, from Thursday to Sunday (North American Timezone), a new playlist opens for Halo 3 players with gametypes that isn't normally available for other matches. Each win gives 2 EXP points, and losses will not take away EXP (however, if you quit out in a game, the standard EXP penalty will be applied). Most of these playlists are unranked, except for the Legendary Brawl playlist, the Living Dead playlist, and the Valentine's Day Massacre playlist. By far, the most featured playlist is the Grifball playlist, including slightly different arenas, and different leagues (spring leagues, summer leagues etc.) Team SWAT changed into a permanent playlist as of May 2008.

Double EXP Weekend Playlists

 * Grifball - This playlist featured RvB's favorite sport gametype.
 * Team SWAT (As mentioned above, this playlist was made permanent)
 * Team Snipers - This playlist focuses on the Shotty Snipers and Team Snipers gametypes as these two gametypes are a rare sight in Team Slayer and Social Slayer playlists. Occasionally, a Spartan Laser and Magnum Pistol spawn gametype will appear in this playlist.
 * Rockets - This playlist focuses on chaotic 8 player FFA Rocket gametypes. Occasionally, a "Splockets" gametype which features a Rocket Launcher and Spartan Laser weapon spawns.
 * Living Dead - This playlist was featured as probably the only playlist where Infection gametypes are played in Matchmaking.
 * Legendary Brawl - This playlist was created to celebrate the release of the Legendary Map Pack release, and featured a 12 person Free-For-All match. This playlist was ranked, allowing many to gain online FFA achievements easier.
 * 3 Ball - This playlist featured a four team Oddball match. 3 Oddballs were placed on the map, and each team needed to battle it out to gain the most points. Other game variants included 3-Low, which required more than one person on a team to be holding a ball to gain points for their team.
 * Fiesta - This playlist featured players on CQB maps with Random weapon spawns.
 * Team Melee - This playlist featured a mix of 3-team slayer and objective games, featuring the Gravity Hammers and Swords.

Holidays
For certain Holidays, such as Halloween, Valentine's Day, and Fourth Of July, playlists were devoted to the day with special gametypes and maps.


 * Living Dead (Halloween) - This playlist featured infection as it's gametype. Special maps were made specifically for this playlist, such as Club Dead (High Ground) and Brain Freeze (Narrows). It should be noted that for Halloween, this playlist was ranked, however when other infection Double EXP weekends came around, they were not.
 * Valentine's Day Massacre (Valentine's Day) - This playlist featured a variation of the hopper Team Doubles. This playlist was strictly Slayer oriented, and was ranked. Bungie had also stated that there would be prizes that would be awarded for certain things done by certain people (such as the most amount of vehicle jacks).
 * Cinco de Mayo (Cinco de Mayo) - This playlist featured a Free-For-All game variant, in which each player spawned with a random weapon (This gametype was known as Fiesta).
 * Fourth Of July (Fourth Of July) - This playlist featured an assortment of gametypes, such as CTF variants, and a gametype called Red Glare. In Red Glare, each player on the team had rockets and Spartan Lasers.

Other

 * Ranked Big Team Battle - This playlist was made a Double EXP playlist for a while to attract players into playing it, as the playlist is in danger of being removed entirely due to a lack of use.