343 has detailed the Achievements set to be added with the Halo 4 Crimson Map Pack next week.
Scheduled for release on December 10, the add-on will cost 800 Microsoft Points and consist of three maps, a new Crimson DLC Matchmaking playlist, and eight new achievements, according to Halo Waypoint.
MS has also revealed that a new game type, Extraction, will be released alongside the Crimson Map Pack - a 5-on-5 objective-based playlist with capture-the-flag-type themes. See the Halo 4 Crimson DLC trailer for more.
The second and third Halo 4 map packs - 'Majestic' and 'Castle' Map Packs respectively - will arrive in February and April, MS has confirmed. Those of you with the Halo 4 War Games Map Pass or Limited Edition version of the game will get access to all three at no further cost, representing a 15 percent discount on their separate prices.