Which Halo game first introduced the Firefight cooperative survival mode?

Halo 3: ODST first introduced Firefight, Halo’s cooperative survival mode.

Firefight debuted alongside Halo 3: ODST in 2009. In this mode, players work together to survive escalating waves of Covenant enemies on a series of multiplayer maps. Teams earn points by defeating enemies while managing limited lives, ammunition, and increasingly difficult enemy sets.

Firefight was designed as a distinct cooperative experience rather than a traditional campaign mission. It could be played solo or cooperatively, with scoring and difficulty modifiers adding replay value. The mode helped expand Halo beyond its scripted campaign and competitive multiplayer.

A common mix-up is Halo: Reach, which also features Firefight and significantly expands it with additional maps, customization, matchmaking options, and playable vehicles. However, Halo: Reach did not originate the mode. Halo 3: ODST is the first game in the series to include it. Later entries, including Halo 5: Guardians and Halo Infinite, continued the broader legacy of cooperative wave-based Halo modes in different forms.