As a treat for Halloween, Bungie has announced that for 27 hours they will be offering zombified playlists for online Halo 3 matches. "It is infection and it is the playlist of the Living Dead," said content manager Frank O'Connor.

Infected gametypes pit human players against one or more "zombies," and although the humans start out advantaged, every fallen soldier comes back as a zombie. There are two main infected styles: Save One Bullet, which gives humans limited ammunition to expedite the failure process, and Creeping Death, which slows down the zombies but also makes them invisible. (A third variant, Creeping Rockets, was noted by Frankie where humans are more armed but zombies are more powerful.) The playlist is ranked, meaning you are more than welcome to use the time and rack up achievements.

All other questions should be directed at this F.A.Q. set up by Frankie (and protected by a demented guard dog, pictured). The playlist of the Living Dead kicks off tonight at 12:01 a.m. PDT (that's 3:01 a.m. ET) and remains in rotation until 3:00 a.m. PDT on November 1.