BLT

BLT is a single-level PWAD for Doom that was released in 1994. It was designed by Neal Ziring. It was released with Lake4 included as a bonus level.

Essentials
A general tip is to make your ammo count. There's little ammo and lots of enemies, so be considerate. You start the map in a small courtyard. In front of you there will be some enemies. Dodge them and next to the pillar you will find the shotgun. Enter the main structure and go up the stairs on the left side. Go to the bottom and press a switch, which opens a door behind you where the blue key is. Now take the opposite path until you reach the bottom and activate the switch. It opens a door on the east side, near the main entrance.

Inside is a small nukage pool. The place is quite dark so take caution. Activate the switch on the column to unlock the entrance. Go ahead and turn right. You will see another switch which opens a door. Follow the path to the end, where you will find a small room with a few imps and cacodemons. Press the switch to the west side and then, on the opposite side, take the teleporter. Now the door on the west side, next to a red torch, will be open.

You will enter a tech corridor. In the first blue door you will find the red key area. Pick it up and return to the corridor. Continue ahead to the end of the path. You will go up a small elevator and pick up the rocket launcher. Destroy the obstacles and continue through the door. The next room contains the yellow key. Pick it up and go back the way you came. Jump over the edge and go back to the beginning of the map. Now, with the yellow key, you can cross the final door and exit the map.

Secrets

 * 1) After going through the first door, turn left.  Near the candelabra on the south wall is a secret door leading to a chaingun and either a computer area map (on easy skill) or an armor (on medium and hard skills). (sector 20)
 * 2) After pressing the switch in the nukage area in the east, take the teleporter.  Ahead of you is a secret door (marked with a greenish texture) leading to a light amplification visor, a soul sphere and an energy cell pack. (sector 61)
 * 3) After getting the yellow key it is necessary to press a switch at the top of a lift to open the door out of this room.  Pressing the other switch here opens a door to the north, revealing an area with a cage containing several monsters.  The south-west corner of this area contains a secret door leading to two energy cell packs (one on easy skill), and possibly either a BFG9000 (easy skill only) or a stimpack (medium skill only). (sector 100)
 * 4) There is a door at the eastern end of the red key room leading to an imp (two on hard skill), a stimpack, and a teleporter. (sector 131)
 * 5) The teleporter in #4 takes you to an area with a partial invisibility.  There is also a spectre here on medium skill, and two spectres on hard skill. (sector 130)
 * 6) Jump down from #5 into an area with several monsters, a megaarmor and eight armor bonuses. There is a secret door, marked with a darker green texture, in the north-east taking you back to the red key room. (sector 117)

Bugs
The linedefs at the side of the door leading to the blue key room (linedefs 136 and 137) have both been assigned Action 11, meaning that pressing either of them will exit the level.

Current records
The records for the map at the Doom Speed Demo Archive are:

The data was last verified in its entirety on November 30, 2021.

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