Wolfenstein 3D is a first-person shooter and a follow-up to Castle Wolfenstein.

There are six episodes and each episode has nine levels (eight regular and a final boss level), plus a secret level activated by an hidden switch somewhere in the eight first levels. Regular levels often feature a maze-like appearance or large areas with many enemies where the player must reach the exit elevator. To do so, he must kill the enemies and, depending on the level, activate "push walls" and/or get silver and gold keys to open certain doors.

Many objects can be found in a level, such as medikits, food, ammo and treasures. There are four weapons, all of them using the same bullets except the knife. The knife and the pistol are given at the start of the level, while the machine gun is either found (usually in secret areas) or picked up from SS troopers, and the Gatling is always dropped somewhere in the level. There are five kinds of enemies (excluding bosses) - Dogs, Soldiers, Officers, SS Troopers and Mutants.

The player character has a number of lives; once he loses the last life, the game ends. To win extra lives, the player has to either find the 1-up item in the level or earn 20,000 points.