In addition to the single-player campaign, Call of Duty 3 features a wide range of multiplayer modes for players to participate in  each team allowing up to 24 on the PlayStation 3 and the Xbox 360, and 16 for the PlayStation 2 and Xbox in a single match. This is only in the online mode.

Call of Duty: Modern Warfare 3's offline multiplayer is now available to play, presumably due to a technical glitch within the game itself. After backing out of attempting to play online, an error message will appear, giving players the chance to play offline.