The agency scooped the business after a pitch against two undisclosed agencies.
Wieden & Kennedy Amsterdam, which has previously produced a number of campaigns for EA, was not involved in the pitch.
As well as producing digital advertising for the game, the agency has also been briefed to produce a TV campaign that will launch in the run-up to its release early next year.
Agency Republic has produced digital advertising for a number of computer games in the past, including Sony Computer Entertainment's Killzone 2, which scooped a silver at this year's Cannes. The appointment comes in the same week that Agency Republic won the digital advertising account for Premier Foods' Hovis after a final pitch against Work Club.
Agency Republic will handle all of Hovis' digital communications. The brand had previously worked with digital agencies on a project-by-project basis, including the Manchester-based Code.