MAP01: Subterra (Master Levels)

Subterra is a map that is part of the Master Levels for Doom II. It was designed by Christen Klie, and is contained in the file SUBTERRA.WAD. In the Playstation Doom port it occupies the twelfth slot and uses the music track "The Broken Ones".

Essentials
Red key

Rise and open either door you can see. Kill the Hell knights and go down. Using the lift, enter the second floor (to the north). The sides of the teleporter lead to the corresponding sides at the starting area. You need to enter the teleporter near the southeast corner. Grab the red key at the tops in the starting area.

Blue key

Return to the lift and use it to get to the bottom level. Open the door at the south. In the blood room, get to the southern side and open the door. Walk around in the cage and press the switch at the end. Return to the lift room but open the red door indicated by bright red rock in both the ceiling and the floor. The rock pedestal with the blue key has lowered. Go down and grab the key. Return to the lift and enter the second floor room where there is another red key door.

Yellow key

Enter the southern room and move on the skull blocks until you enter a teleporter. At the intersection, enter either the western or the northern door. The latter route is faster. On the grounds, go to the south-west of this area. Press the switch that lowers the wooden bar with the yellow key. Get to the top either by lowering the wooden lifts near the yellow key door (a much faster way) or by using the teleporter at the south-east. Once on the top, you will see two cages with monsters. Go to the eastern end, walk around the second cage (or run over a gap) and grab the yellow key.

Exit

Drop down to the grounds and enter the western door indicated by yellow rock in both the floor and the ceiling. Open the blue door at the south. An alcove to your right will open along the blue door. It contains a button to turn on the lights in the southern room. Enter the place. Carefully walk on the steps until you reach the button at the end. Press it and get back to the room where the yellow key door is. Now you can enter the nukage in the north without getting trapped. Flip the switch at the end of the nukage pool.

Secrets

 * 1) To get the soul sphere in the south-west nukage, you have to enter the teleporter pad either from the north or from the east. (sector 178)

Current records
The records for the original map on the Doomed Speed Demos Archive are:

Player spawns
This level contains four spawn points:
 * 1) facing south-west. (thing 173)
 * 2) facing east. (thing 185)
 * 3) facing south. (thing 186)
 * 4) facing east. (thing 187)

Things
This level contains the following numbers of things per skill level:

Differences between PC and PlayStation versions

 * 1) An exit sign was added above the exit switch.
 * 2) The two doors in the starting area are opened automatically when the player approaches. The trigger also opens a pair of doors at the lift. These lift doors were removed in the PlayStation version. This allows players to grab the health and armor bonuses while playing in deathmatch.