STR56: Phobos Anomaly (Stronghold: On the Edge of Chaos)

Stronghold secret maps
STR50: Duke it Out STR52: City of Silence - Apocalypse STR54: Fortress of Damnation STR56: Phobos Anomaly
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 99 Secret maps

This level occupies the map slot STR56. For other maps with a non-standard slot, see Category:Non-standard map slots.

STR56: Phobos Anomaly is the fourth secret map of Stronghold: On the Edge of Chaos. It was designed by Björn Ostmann (Vader) and Daniel Gimmer (Tormentor667), and uses a custom music track.

This level uses the "Core" mode, where the objective is to prevent monsters destroying a computer core.

Walkthrough

Map of Phobos Anomaly

Letters in italics refer to marked spots on the map. Sector, thing, and linedef numbers in boldface are secrets which count toward the end-of-level tally.

Essentials

As the level starts, there are two passages to the left and right of player one - the left (west) passage leads to the core room, while the right (east) leads to a room with two health, two ammo, one weapon and one powerup pad. Head north from the starting point to find a shotgun and shells, then follow the passage up to a pentagram arena and continue heading north to find a chaingun at the north point of the pentagram.

Monsters will spawn from a magma pool at the north end of the level and head south until they reach the pentagram arena; they will then head south-east or south-west around the arena to some teleporters that will send them to the glowing pentagram in the middle of the arena. From this point they will head south to the players' start point then west to reach the core.

Wave	Enemies	Weapons and ammo given	Armor and powerups given
1	Ten imps Five demons	-	Seven stimpacks
2	16 catharsi Ten imps Eight demons	Three shotgun shells Two boxes of bullets Two clips Box of shotgun shells Chaingun	Eight stimpacks
3	Ten spectres Eight demons Three Hell knights	Three boxes of bullets Two boxes of shotgun shells Super shotgun	Eight stimpacks Armor
4	Eight spectres Eight blood demons Six knights	Five boxes of bullets Two boxes of shotgun shells Two shotgun shells Clip Landmines	Ten stimpacks Armor
5	14 demons 14 spectres Eight barons of Hell	Seven boxes of bullets Four boxes of rockets Four shotgun shells Two boxes of shotgun shells Two rockets Rocket launcher	12 stimpacks Backpack
6	20 hellions Eight revenants Two arch-viles	Six boxes of rockets Five boxes of bullets Four boxes of shotgun shells Four energy cells Two shotgun shells Plasma gun	14 stimpacks
7	20 shadows 15 wickeds 12 Hell warriors	12 boxes of rockets Six boxes of shotgun shells Four boxes of bullets Three energy cells Energy cell pack Stunner rifle	14 stimpacks Three medikits Megaarmor
8	20 spectres Ten barons Eight nightmare demons	11 boxes of rockets Ten mines Five boxes of shotgun shells Four boxes of bullets Four energy cells Two shotgun shells Energy cell pack Rocket	Ten stimpacks Six medikits Supercharge
9	20 guardian cubes Five bruiser demons	16 boxes of rockets Six boxes of shotgun shells Three energy cell packs Two boxes of bullets Energy cell BFG9000	Ten stimpacks Eight medikits
10	42 suicide bombers Two terminators	14 boxes of rockets Six boxes of shotgun shells Four energy cell packs Three energy cells Two shotgun shells Box of bullets Gas canister Flamethrower	Ten stimpacks Ten medikits Megasphere
11	25 phase imps Four archons of Hell	Ten boxes of rockets Six boxes of shotgun shells Three energy cell packs Three energy cells Two shotgun shells Box of bullets Gas pack Pyrocannon	12 medikits Ten stimpacks Megasphere Quad damage
12	Five pyrodemons	Eight boxes of rockets Three energy cell packs Three energy cells Two gas packs Two boxes of bullets Box of shotgun shells	14 medikits Ten stimpacks Megaarmor Supercharge

Completing this level will award 1,500 bonus credits.

Secrets

There are no official secrets on this map.

Speedrunning

As this level does not contain official secrets, the NM 100S category is redundant.

Current records

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

Run	Time	Player	Date	File	Notes
UV speed
NM speed
UV max
UV -fast
UV -respawn
UV Tyson
UV pacifist

The (absence of) data was last verified in its entirety on February 21, 2022.

Statistics

Map data

Things	262
Vertices	7006*
Linedefs	9748
Sidedefs	17767
Sectors	2787

* The vertex count without the effect of node building is 7006.

Things

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

Single-player
Weapons	1-2	3	4-5
Shotgun	1
Chaingun	1
Ammunition	1-2	3	4-5
Clip	2
Box of bullets	2
4 shotgun shells	9
Box of rockets	3
Health & Armor	1-2	3	4-5
Medikit	2
Miscellaneous	1-2	3	4-5
Teleport landing	10
Power core	1

Cooperative
Weapons	1-2	3	4-5
Shotgun	1
Chaingun	1
Ammunition	1-2	3	4-5
Clip	2
Box of bullets	2
4 shotgun shells	9
Box of rockets	3
Health & Armor	1-2	3	4-5
Medikit	2
Miscellaneous	1-2	3	4-5
Cooperative start	8
Teleport landing	10
Power core	1

Inspiration and development

This level is based on the pentagram arena from Knee-Deep in ZDoom's Z1M8: Phobos Anomaly. After completing the first wave, a message is displayed asking if the player feels nostalgic before jokingly noting that the level looks nothing like the Phobos facility.