MAP31: Mortar Combat (Community Chest 4)

MAP31: Mortar Combat is the secret level of Community Chest 4. It was designed by Stuart Rynn (Forty-Two), and uses the music track "Mortar Combat," which he composed specifically for the map.

This level contains a secret exit leading to MAP32: Mutare. Completing this level through the normal exit takes the player to MAP16: The Forgotten Base.

Essentials
To reach the secret exit, you need to press several skull switches. Some of these switches reveal items or monsters (usually arch-viles) inside of them, but they also remove the barriers to the secret exit. There are 13 switches in total:
 * One is right at the beginning.
 * In Secret #2.
 * Three skull switches are in Secret #3.
 * On the high ledge at the eastern part of the map; approaching it reveals a mancubus and a switch.
 * In the southeastern part of the map, climb the steps up to the ledge with Hell knights, then go eastward, and a wall is revealed with a baron of Hell and the switch.
 * In the southern part of the map, just before the arachnotron, is a hall that leads to a switch.
 * In the southern part of the map where an arachnotron is stationed, there are two switches.
 * In Secret #4.
 * After you open the skull doors, head for the northwest portion of the map and next to the stairs leading down, there is a switch.
 * Past the blue key door, and near the normal exit, is the final switch. After pressing it, look south of it and open the wall. If you had pressed all of the other switches, you should access the secret exit, where you will be killed by barrels just before exiting to MAP32: Mutare.

Secrets

 * 1) In the western part of the map, there is a rocket launcher with several rocket boxes. You need to head onto the platform behind the rocket launcher platform; this one has an arachnotron on it. When you climb the steps to it, the wall in front of you lowers. One of the walls it reveals is lighter than the others, use it to get a medikit. (sector 661)
 * 2) A bit north of Secret #1 there is a large door you can open. Do so, and when you enter the next hall, look towards the walls on the lift side. Spot the one that is textured differently, and open it to gain access to the revenant's platform, where you can find one of the switches that allows access to the secret exit. (sector 63)
 * 3) Enter the blood canal in the northern part of the map (a bit east from Secret #2). Look towards the wall on the right for blood drips under it. This is a fake wall you can go through with a switch behind it. Press the switch, then leave the blood canal to the west. Back in the hall with several metal beams, use the eastern side of the northeastern beam to lower it as a lift, and ride it up, then open the wall to the right to find three of the switches that open up the secret exit. (sector 311)
 * 4) At the southwestern part of the map, near the wall of Hell knights, climb the steps to the imps' ledge and press on the brick wall that is lighter than the rest to reveal a passage to the revenant's platform and a switch. (sector 56)
 * 5) After you open the skull doors, head for the northwest portion of the map and next to the stairs is a small ledge you can sidle across (along with one of the switches that opens the way to the secret exit). Sidle until you are able to drop into the blood pool and then do so (alternatively, you could utilize an arch-vile jump to enter the blood pool). In the southwestern corner of the pool is an opening where you can find boxes of rockets, as well as a teleporter leading you onto the arch-vile's platform and an armor. (sector 236)
 * 6) The sector just before the secret exit teleporter counts as a secret. (sector 613)

Current records
The records for this map at the Doomed Speed Demos Archive are:

Miscellaneous demos
''This information was last verified in its entirety on January 23, 2018.

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