Halo 4 forge mode detailed, in the works at Crimson Alliance dev

Crimson Alliance developer Certain Affinity is behind Halo 4's editing mode, Forge.

Certain Affinity is an Austin studio which worked on a couple of Halo map packs in the past. Polygon reports the developer announced its involvement during Rooster Teeth this weekend, while also detailing some of the system's new features.

In particular, players can lock down objects, and objects are highlighted and named to make it easier to move them around. Items can be duplicated quickly and magnetised to connect to other objects, and a new lighting system means you can drop shadows all over the place.

A new system called Player Trait Zones will change parameters when players enter, for example slowing them or letting them jump higher, and a new object called Grav Volume can even alter or reverse gravity.

Halo 4 is an Xbox 360 exclusive and the first in the series to be developed outside Bungie; it's due in November.