United Offensive (an expansion pack to Call of Duty) features an enhanced multiplayer experience with all new maps, weapons, and three new modes of play: "Domination," "Capture the Flag," and "Base Assault." Players take sides as Americans, Germans, Russians or British and wage war in an Axis versus Allies onslaught and are able to commandeer multi-slotted tanks, jeeps, and trucks to add extra punch to the battles. Teamwork in battle is key as COD implements a ranking system, which rewards players who work as a team or achieve points by accomplishing mission objectives.