The Exterminatus DLC for Warhammer 40,000: Space Marine will be released on Tuesday, 25th October, Eurogamer can exclusively reveal.

The free add-on will hit all three platforms - PC, PS3 and Xbox 360 - at once. Note that the PlayStation Store updates a day later in Europe each week, on Wednesdays.

With the Exterminatus DLC comes four-player online co-op. You play a special mode fittingly called Exterminatus, which pits Space Marines against Orks and the Forces of Chaos.

You can be either a Tactical Marine, Devastator or Assault class, and you can use perks unlocked in competitive multiplayer to give you an edge. Co-op progression will apply to your multiplayer ranking, too. Teams will be scored on their performance, and benefit from multipliers and dynamic challenges along the way.

Exterminatus will have two scenarios to begin with: Assault on Hab Center Andreas, and Escape from Kalkys Facility.

Developer Relic Entertainment last night told Eurogamer there will be more DLC to follow the Exterminatus mode.

"There are some plans [for more]," producer Andy Lang told us. "We're working on some other DLC."

He was reluctant to go into detail, but said that with future DLC "there will be a free component to them as well as some paid components".

An accompanying Relic PR confirmed that "we'll have both" - referring to premium and free DLC.