Today marks the release of Killzone 3's multiplayer as a free, standalone product. To celebrate this occasion and mark the game's first anniversary, Sony will turn up the juice this weekend with a double XP event.

Dubbed Killzone 3 Multiplayer, the free standalone product features the Guerrilla Warfare, Warzone and Operations game modes, including all launch and DLC maps from Killzone 3 proper. Players are free to partake until they attain Sergeant I rank. To continue past then, you'll have to pony up $15.

Double XP kicks off on Friday at 8am PT and lasts until 2am PT on Monday. Those playing the free version of Killzone 3 multiplayer will not earn double XP this weekend.