The Fist is the basic unarmed weapon in Doom. Unlike previous games the fists cannot be selected for individual use, however players get a chance to use them when acquiring the Berserk power up, or if they have no weapons available in SnapMap mode.
Their availability only on Berserk is due to the Pistol having infinite ammo, and therefore always being available. Furthermore, the command F, which is used for Glory Kills, can also perform another melee attack outside of Glory Kills by which the player strikes the enemy with his weapon directly, paralleling Doom 3's flashlight attack. This attack is usually performed inadvertently when the player "misses" a Glory Kill due to the enemy recovering from being stunned, but it can still occasionally kill weaker enemies such as Possessed or Imps.
When under the effects of Berserk, the fists are very useful in close melee attacks; they Glory Kill any and all enemies, except bosses.