Which Assassin’s Creed game introduced online multiplayer to the main series?

Assassin’s Creed: Brotherhood introduced online multiplayer to the main Assassin’s Creed series.

Released in 2010, Brotherhood added competitive multiplayer alongside its single-player campaign. Players controlled different Templar-aligned characters in modes built around stealth, pursuit, disguise, and carefully timed assassinations. The multiplayer design turned familiar series ideas—blending into crowds, reading behavior, and striking from concealment—into contests between human players.

The single-player story continues Ezio Auditore’s journey after Assassin’s Creed II and is centered on Rome. Because Brotherhood is often remembered mainly for expanding the single-player world and adding Assassin recruitment, its multiplayer debut can be overlooked. Assassin’s Creed II did not include this online competitive mode, while Revelations followed in 2011 and continued the multiplayer feature. The original game also lacked the main series’ later online character-versus-character format.