Energy cell

The cell is the unit of ammo used by the plasma rifle and BFG 9000. Each BFG shot consumes 40 cells, while the plasma rifle can be fired one cell at a time (although this takes some concentration, as its rate of fire is very high).

Perhaps confusingly, the games' instruction manuals show "Cell" as an ammo pickup. This pickup actually contains 20 cells (40 at I'm Too Young To Die and Nightmare! skill levels), and the game calls it an energy cell. Other sources call this pickup a cell charge.

Each cell fired from the plasma rifle does 5-40 hit points of damage (determined using Doom's pseudorandom number generator). BFG damage calculations are rather more complex, but a direct hit inflicts 100-800 points, and a nonstandard form of blast damage may also occur (which affects even bosses normally immune to blast damage).