Start the game by entering the command "WOLF3D /NEXT". While playing, press TAB + CTRL + ENTER to access the cheat codes above. Version 1.0 had an extra cheat as well:

TAB+N   walk through walls

Start the game with the command "wolf3d goobers". While playing, press LEFT ALT + LEFT SHIFT + BACKSPACE at the same time to enable cheat codes. To use them, hold any of the key combinations below:

TAB+B   change the border color
TAB+B   Border color
TAB+C   display statistics for the current level
TAB+E   warp to the end of the current level
TAB+F   displays your coordinates
TAB+G   God Mode
TAB+H   removes health
TAB+I   boost your weapons, health and ammo
TAB+M   shows current memory usage
TAB+P   pause the game
TAB+Q   quit the game
TAB+S   activates a slow-motion mode
TAB+T   graphics test
TAB+V   adds vertical-blank interrupts for slower machines
TAB+W   to warp to any level
TAB+X   gives you "Extra Stuff" (?)

While playing, press the keys "I", "L" and "M" at the same time. This code will give you 100% life, 99 ammo, both keys, and all of the guns. But beware: this code takes away your score too.

In the room at the end of the first level with the grey door leading to the second level, there is a secret passage. Immediately upon entering, turn right. In the corner of the right wall and the wall with the door that you just came through, press the SPACEBAR near the right wall to reveal a secret passage. Head straight until you hit a wall. Turn right and press the SPACEBAR again to reveal a second passage. There will be a grey door in this room leading to a secret level with purple walls.

When you are fighting Hans Grösse, boss of episode 1, go to the main room, the one with all the wall hangings and rows of columns. Go to the left side of the room, there should be three golden swastikas hanging on the wall. Walk up to the middle one and press SPACE. This will open a secret door which leads into a room containing health, ammo, and the chaingun. Visit this room before you take on Hans, and revisit it if you exhaust your ammo during the fray, or take too many hits.