MAP18: The Courtyard (Doom II)

MAP18: The Courtyard is the eighteenth map of Doom II. It was designed by Sandy Petersen and uses the music track "Waiting For Romero To Play".

Walkthrough
To get out of the first room, you must shoot the door (A - you can also use your fist or chainsaw to open it). Behind the door is a trooper and some imps. Shoot them, collect all the shotgun ammo, and the shotgun, and proceed through the archway (B) into the courtyard.

When you get into the courtyard (C), RUN all the way straight to the staircase across from you (don't climb it). Facing the staircase, go through the opening (D) to the left of it. Over here, collect the Yellow Key (E). Now go back and up the stairs (before the Demons trap you), and up here, go all the way right, then left, and left again to the Yellow Door (F). Open it.

In here, take the teleporter (G) before the Cacodemons come and get you. When you teleport into this room, kill the Cacodemons in front of you. Now drop down to the floor below you. Down here are loads of Health Potions. The Blue Key (H) is scattered down here too. Pick it up. Also down here are a few pillars. One of them has a switch (I). Hit it, and to the left of you a staircase has risen to a teleporter (J). Take it.

You'll be teleported in the Yellow Door room. Now go right, down into the floor below you, and RUN all the way straight to the opening across from you, before you get caught in a huge enemy mess. Back in this same room, go right, through the opening, and back into the starting room. In here, open the Blue Door (K). Take the teleporter in this room.

Trivia and other points of interest

 * 1) The main theme for this level's BGM is reminiscent to the verse riff of Pantera's "This Love".
 * 2) There is a slime river near the beginning of this map, the river has several pillars with the marking of "Poison" written on it. Be careful about it because if you fall into the slime river, you can't get back out.
 * 3) In sector 87, there is a box of bullets that hovers at the top of the sector. This is because the object barely clips outside the sector's boundary.

Secrets

 * 1) In the northwest corner of the courtyard is a triangular area of grass between a couple buildings (for easier identification, the area where you grab the yellow skull key). Step into the northern corner of the triangle (the "non-illuminated" portion of it) to be teleported an otherwise unreachable ledge in the maze area.
 * 2) Inside the maze area are two blue-walled skull switches. The one in the southeast corner of the maze has a secret alcove containing a chaingun behind it.
 * 3) After passing through the northeast trail of armor/health bonuses radiating from the central pillar in the courtyard, a door opens on the west side of the yard. Behind it is a spiraling hallway leading to a BFG 9000.
 * 4) After passing through the northwest trail of armor/health bonuses radiating from the central pillar in the courtyard, an alcove opens in the northeast corner of the yard. Close to this alcove is a "+"-shaped structure. Press the switch on its northeast side to lower a teleporter back in the alcove you just opened. Go through to be taken to a new secret area.

Bugs

 * 1) Sector 15 is a hidden aperture, with ceiling and floor heights set to 144 (the floor later drops to 16). Bordering it on the sides are two linedefs (451 and 459) that are set as two sided. The front sidedefs of both linedefs are part of sector 15, but the back sidedefs are each defining unique sectors (16 and 38) which are set to floor heights of 0 and ceiling heights of 192. As these sectors only have one sidedef each and no associated middle texture, they open to the outside map. One provides a view of an adjacent room, while the other provides a hall of mirrors shimmering effect.
 * 2) At the beginning of the level, after opening the door triggered by either shooting or punching/chainsawing, the "trigger" for the door remains active even after it is open. Therefore, if you stay inside the room and shoot at the imps outside, every gunshot towards (and through) the door sets off the "switch flipped" sound effect.
 * 3) The same bug also occurs if the southern wall of the "+"-shaped structure is shot open to reveal the Cacodemons.

Records
The Compet-N records for the map are: