Energy cell (Doom)

An energy cell is a dark gray ammo container shaped like a box and displaying small green lights or s. It is used to power the plasma gun and the BFG9000, holding enough energy to fire the lesser weapon 20 times (or 40 on the I'm Too Young To Die and Nightmare! skill levels). While the plasma gun can be discharged one unit at a time – with difficulty, due to its rapid rate of fire – each BFG shot consumes 2 whole cells (or 1 on NM and ITYTD).

Each shot from the plasma gun does 5-40 hit points of damage, determined using Doom's pseudorandom number generator. BFG damage calculations are more complex; a direct hit inflicts 100-800 points, after which additional energy damage is discharged, that can take the total damage into the thousands of hit points.

Appearance statistics
In the IWADs the energy cell is first encountered on these maps per skill level:

The IWADs contain the following numbers of energy cells per skill level:

Doom RPG
In Doom RPG, the plasma pickup is called a plasma box. It gives the player either 4 or 10 cells.