Assassin's Creed 4 multiplayer offers double XP on PS3, PS4

Assassin's Creed 4: Black Flag developer Ubisoft Montreal is running a PlayStation-exclusive multiplayer event over the weekend that begins this afternoon, according to a post on the official PlayStation forums.

The event, "Uncertain Alliances," asks players on PlayStation 3 and PlayStation 4 to work as a team, whether they're hunting down their opponents or trying to stay hidden. The developers will provide certain objectives for the community to complete, each of which will unlock some exclusive content:

Individual Goal: Earn a Focus Bonus (15 times)
Individual Reward: 1 Patron Picture for each playable character

Participation Goal: Complete a session in the event playlist
Participation Reward: Achieve the title "The Opportunist"

Players can also log in to Black Flag's multiplayer component to see the collective community objective, which will provide them with exclusive Assassin costumes upon completion.

In addition to the particulars of the Uncertain Alliances event, Ubisoft will give players double XP for the duration of the weekend. Both promotions run from 4 p.m. ET today, Jan. 17, through 2:59 a.m. ET on Monday, Jan. 20.