Save One Bullet is a variation of Halo 3's Infection multiplayer game type. It is essentially the same as normal Infection, except that no weapons spawn on the map, so the human and Elite team must be careful to conserve ammunition. It is advised to take the dead players weapons (human or zombie) when possible, and to use head shots.
Zombies have full shields and a longer jumping distance. They spawn with the Energy Sword. Humans have limited ammo, and spawn with the pistol and shotgun.
- The term "Save one Bullet" most likely refers to the concept in horror movies, in which characters save one bullet to shoot themselves rather than be consumed by zombies.
- "Save one Bullet" is the official version of "Zombie Panic" where ammunition is limited, and the humans have to conserve every shot they have left because there is no ammo for them on the maps.
- In Save One Bullet, a Human can acquire more ammo by jumping off of the map, or being betrayed by a teammate.
- Save One Bullet's ammunition settings have since become standard of Infection gametypes.