As well as bringing the usual assortment of balance tweaks plus fixes for bugs and exploits, Title Update 6 will add a new casual 'Social' matchmaking option.

Epic has yet to reveal when the update will go live but says the event will be celebrated with a sale on the 'All Fronts Collection' downloadable content megapack, as Social matchmaking requires players have all maps. The full changelog follows.

Improvements
Title Update 6 makes these new improvements:

• Adds a new public multiplayer match option called Social Xbox LIVE (aka player matches), open to anyone who owns all downloadable maps (that is, All Fronts Collection). We'll be having a promotion that will dramatically reduce the cost of the All Fronts Collection.
  
  
• You can join Social Matches in progress and can quit any time without penalty, although players who quit a match early don't receive earned experience (XP) from that match.
• Social matchmaking lets your party join a match in progress. If a match is not found, your party hosts a new match, filling any empty player slots with bots.
• Social Matches automatically cycle to the next map without further matchmaking.
• Teams are rebalanced between matches based on XP level without splitting parties.
• If you quit, your spot is taken by a bot until a new player joins the match. That new player can join while the match is in progress.
• If you join a match in progress, you are assigned a team based on XP level and party size.
• If you join a match in progress, you replace a bot at the earliest opportunity: at the first bot's death for respawning game types (for example, Annex) and at round completion for Warzone, Execution, and Wingman.
• Social leaderboards become part of the War Journal.
• Renames Public Matches to Ranked Xbox LIVE Matches to differentiate these from Social Xbox LIVE Matches, and adds some improvements to these matches.
  
  
• Improved host selection using bandwidth testing and previous hosting data has been added.
• Before the match begins, teams are balanced based on XP without splitting parties.
• Renames Private Matches to Custom Xbox LIVE Matches and makes these matches invite-only.
• Adds the ability to join Horde sessions that are in progress.
  
  
• In Social Horde, you can join a session in progress through matchmaking and you are able to continue your session from the last wave you failed without starting over.
• In Ranked Horde, you can join a session in progress only through invites.
• If you join a session in progress, at the end of the session you receive the score you achieved during the time you spent in the session.
• Improves the precision of weapon selection using the D-pad.
• Improves client-side hit detection for ballistic weapons.

Exploit Fixes
Title Update 6 fixes these possible exploits, where under certain circumstances:

• Execution rules could be ignored when using certain weapon types.
• On the Subway map, you could get outside of the playable environment by sliding into cover and rolling between a train car and the side of tracks.
• On the Blood Drive map, you could get outside of the playable environment in various locations.
• Players could grief other players on Submission, Annex, King of the Hill, and Guardian games by preventing the objective from being completed while racking up experience. Title Update 6 adds match time limits to each of these game types to prevent this practice.

General Fixes
Title Update 6 fixes these other issues as well:

• An issue that could cause your profile to be overwritten, erasing XP level, and achievement progress.
• An issue that could cause a campaign save slot to be overwritten if you previously chose to continue without saving and then signed in.

Balancing
Title Update 6 makes these balancing changes:

• Changes the Gnasher Shotgun pellet pattern to increase hit consistency.
• Changes the Guardian game type to select the leader based upon XP level (highest to lowest).

Oh, also... firing delays after roadie run and evades are reduced.