Nevermind the bullets; how much all these coffins costin' ya?
— The Engineer on posthumous costs
Ammo, or ammunition, is a resource that contributes to a player's weapon ammunition supply. Ammunition can be found in the form of Ammo crate pickups, dropped weapons, or destroyed building parts. Ammo is universal, meaning that ammo in the form of any dropped weapon can be used in any other weapon; ammo acquired from a dropped Flamethrower will still be usable as Sniper Rifle ammo, and can also be used to fill the Cloak charge for the Spy's Invis Watch and Dead Ringer. Additionally, the amount of ammo in a pick-up is applied to all weapons equipped, not just the one currently held. Reloading cannot be performed without having reserve ammunition. Should the player expend all ammunition with a weapon, it will be automatically switched with another and will be unavailable for use until more ammo is obtained.
Ammo pickups come in three different sizes. Each one refills a different percentage of their player's total ammo capacity (The ammunition that can be stored in a weapon's magazine is not factored into this percentage), as well as the Engineer's metal, and the Spy's Invisibility Watches (excluding the Cloak and Dagger). There are also several other sources of ammo that can be found:
- Ammo boxes
All Ammo crates have a 10 second respawn time.
- Small Ammo Pickup: Refills a fifth (20%) of each weapon's ammo capacity.
- Medium Ammo Pickup: Refills half (50%) of each weapon's ammo capacity.
- Large Ammo Pickup: Refills all (100%) of each weapon's ammo capacity.
With the exception of stickybomb debris, provides 50% of each weapon's ammo capacity, but considerably less metal and Cloak.
- Dropped items
- Weapons dropped from dead players: Refills half (50%) of each weapon's ammo capacity. Fills approximately 25% of a Spy's Cloak.
- Toolboxes dropped from dead Engineers: Refills all (100%) of each weapon's ammo capacity.
- Other sources
- Level 1 – 20% / sec
- Level 2 – 30% / sec
- Level 3 – 40% / sec
- Note: Enemy Dispensers will also refill ammo and Cloak if a Spy disguises as the enemy team. This has no effect on the operation of friendly Dispensers.
- Carts: 20% / sec
- Resupply lockers: Refills to 100% ammo for all weapons (as well as refilling the current magazine).
February 19, 2008 Patch
- Dropped weapons now replenish half of your max ammo when picked up.
August 23, 2011 Patch
- Added TF birthday replacement models for health kits and ammo packs.