Backpack



The backpack is a powerup that doubles the player's ammo-carrying capacity. After picking up the first backpack, the player is able to carry up to 400 bullets, 100 shotgun shells, 100 rockets, and 600 plasma cells at once. The backpack also gives 10 bullets, 4 shotgun shells, 1 rocket, and 20 cells when picked up (20, 8, 2 and 40 on I'm Too Young To Die and Nightmare!). Backpacks after the first to not change the ammo-carrying capacity, but do add to the ammo being carried (when less than the maximum).

The backpack's effect lasts until the end of the episode in Doom and until the end of the game in Doom II/Final Doom.

Appearance statistics
The IWADs contain the following numbers of backpacks: