As promised, here is an example of the method presented in the earlier article Random Mega Generation Via 5 Room Iterations. The method aims to create a large scale megadungeon in modular chunks with minimal work.

Our first step is to create the main map by combining a random number of 5 room dungeons. Each room will represent a realm, a large dungeon area with an overarching theme and several smaller sub-areas.

The Evil MuleI started with a 1d4 roll for the number of 5 room chunks to include in my main map and got a result of 1. I followed this up by rolling a d66 to determine which 5 realm set to use and got a result of 23 which is “The Evil Mule”.

This setup is just the starting point. I shifted about the positions of the rooms and added a connection that wasn’t present in the original base model (shown in red). Finally I numbered the realms to make keying them easier. Here is the final result:

RealmsFrom here I can detail each realm using the simple template provided in the original method:

Name:
Level:
Terrain:
Monsters: (S), (M), (L)

Description

Here’s a rundown of all 5 realms:

1) Name: The Undercity
Level: Low
Terrain: Ruins of all types
Monsters: Scavengers(S), Mechanicals(M), and Oozes(L)

This is layers of ruins and dungeons. Sewer, catacombs, built over city blocks all over an abandoned dwarven fortress. Scavengers from the city above and goblin tribes below abound as do mechanical critters from the dwarven city and oozes of all types from the sewers. Fun place.

2) Name: Steam Caverns
Level: Medium
Terrain: Natural caves
Monsters: Plants(S), Lizards(M), and Mists(L)

Vertically, these caves are situated above area 4 which is volcanically active, and a lot of the steam created by leaks from area 3, which is filled with water, ends up in the Steam Caverns. These caves are apparently created by old volcanic activity but are very much alive, full of steam and moisture and heat, giving them a “lost world” feel as well as a “haunted” feel.

3) Name: Unterzee
Level: Medium
Terrain: Underground sea, islands, etc…
Monsters: Pirates!(S), Ichthyic Humanoids(M), Sea monsters(L)

A series of flooded caves and a huge underground sea

4) Name: Lava Heart
Level: High
Terrain: Crusted magma sea with bleak stone islands
Monsters: Magma Hazards(S), Roman themed fire elemental dwarves(M), Fire Giants(L)

A set of scorching hot caves, magma tubes, and blasted fumaroles around a large cavern with a crusty magma “sea”.

5) Name: Shining Hell
Level: High
Terrain: Volcanic slag, monolithic spires, citadels of jagged glass
Monsters: Earth elementals(S), glass hazards(M), Demons(L)

Caves filled with glassy slag, glowing gems and fortresses crafted from wicked slabs of volcanic glass.

From here, each realm can be detailed in turn, but one of the major selling points of this technique is that it’s created in discrete parts which aren’t dependant on one another, so it’s easy to just create a single realm. In this case, I’m just going to focus on the first realm on the list, the Undercity.

The PawThe MooseJust like the main map, a realm map starts with a random number of sets of 5 rooms, each room representing a single zone. For this example I rolled a d4 and got a result of 2 sets of 5 zones. Rolling a d66 twice, I got results of 51(The Paw) and 44(The Moose). I combined these maps and tweaked the results, adding some additional passages (shown in red) and even a secret path between two zones (shown in dashed blue). In the map below you can see that zones 1-5 came from The Paw and 6-10 came from The Moose.

The Undercity Each of these zones can now be detailed with a template similar to the one used for realms:

Name:
Type:
Level:
Terrain:
Monsters:

Description

Though I only need to detail enough zones to keep my players busy, 10 isn’t such a big deal so here’s a complete rundown:

1) Name: Sewers
Type: Controlled
Level: Lower
Terrain: Human city sewers, Half flooded brickwork tunnels full of detritus and offal
Monsters: Scavenging animals(S), Human thugs and rogues(M),Oozes and slimes(L)

Sewers from the city above.

2) Name: Natural Caves
Type: Mixed
Level: Lower
Monsters: Surface Humanoids(S), Brigands(M), Surface Predators(L)

A series of natural caves that connect to the surface full of goblins, bandits and other predators.

3) Name: City Ruins
Type: Mixed
Level: Lower
Terrain: Bricked over abandoned buildings, forgotten sub basements and crudely carved caves
Monsters: Wicked Treasure Hunters(S), Degenerate Cannibals(M), Dire predators(L)

Ancient city ruins that were bricked over instead of renovated. Old sewer tunnels pass through this area.

4) Name: Dark Catacombs
Type: Mixed
Level: Standard
Monsters: Degenerate cultist(S), Humanoid undead(M), Lesser Demons(L)

A section of even older catacombs of unknown origin, constantly cloaked in some sort of darkness. The most deranged of the cannibals from Zone 3 make their way here to worship and summon the dark beings that haunt this area.

5) Name: Deep Caverns
Type: Standard (Doesn’t have a unique population of it’s own)
Level: Standard

A cluster of limestone caverns deep below the city.

6) Name: The Abyss
Type: Mixed
Level: Standard
Monsters: Goblinoids(S), Gnolls(M), Crazed broken mechanicals(L)

A great chasm with a massive trash pit of rusty dwarven castoffs from ages past and the terminus of the offal from the sewers. Myriad tribes of humanoids war over the best garbage new and old.

7) Name: Crystal Caverns
Type: Controlled
Level: High
Monsters: 7.5hp orcs(S), Shadows(M), Crystalline Reapers(L)

A set of caves full of huge, nigh indestructible crystals. The toughest tribe of humanoids from Zone 6 have staked out this defensible location unfazed by their occasional loss from the shadowy undead and crystal-scythed insects that roam the caves.

8) Name: Dwarven City
Type: Mixed
Level: Standard
Monsters: Humanoid scavengers(S), Desiccated Dwarven undead(M), Mechanical Guardians(L)

The ruins of a dwarven city. Occasionally explored by the humanoids from Zone 6. Populated by the dried up zombie remains of it’s original inhabitants and it’s mechanical guardians.

9) Name: Dwarven Citadel
Type: Controlled
Level: High
Monsters: Desiccated Warriors(S), Mechanical Guardians(M), Ethereal Abominations(L)

The Fortress of the dwarves. Legions of armored undead still patrol its halls supported by mechanical guardians. Strange abominations wander the hallways largely ignored by and occasionally preying upon the defenders.

10) Name: Dwarven Palace
Type: Controlled
Level: High
Monsters: Mechanical Guardians(S), Ethereal Abominations(L), Desiccated Sages(L)

The dwarven palace, lit by weird lights. Protected by the same types of guardians as the fortress, these are often commanded by still sentient undead dwarven casters who even bend the strange abominations to their command. Magic mirrors in the palace allow transport to the polished crystals in the caverns below.

The next step is to make a map and key for each zone. Just as before, I only need to stay a few steps ahead of my players, so I’m just going to look at a single zone. In this case, The Abyss looks like an interesting setup.

As before, each zone is made of several sets of 5 rooms. Rolling a d4 for The Abyss, I get a result of 4. Rolling for each set I get results of 32 (Fauchard Fork), 45(The Moose), 43 (The Moose), and 24(The Evil Mule).

The ForkThe MooseThe MooseThe Evil Mule

The main point of the Abyss is the giant rift full of war camps in the middle, so I’m arranging these building blocks Into a middle “strip” and using that to represent the abyss (in red) with spots of interest as numbered areas. The outside rooms are caves coming off of the center. The “interior passages” are just for illustration’s sake so the original 4 structures can be seen. To keep things brief I won’t detail all 20 rooms, just a random selection. For population, I’m using the mixed Squabblers table. Where I have a choice between two options I’m just rolling odds or evens.

3) d12 roll: 10
Result: 1ZL or 4RS
1 Crazed broken mechanical: Some ancient piece of rusted out dwarven war machinery has lurched to life in this area attacking everything that comes near

4) d12 roll: 4
Result: 6ZM or 12RS
12 Scavengers: A group of pestilent goblins fights over choice pickings in a pile of filth here.

5) d12 roll: 4
Result: 6ZM or 12RS
12 Scavengers: A group of treasure hunters from the surface has dug in here. Some of them keep a lookout while others scavenge bits of rare metals off the remains of an inactive mechanical. They may not be hostile if approached carefully.

8) d12 roll: 9
Result: 1ZL or 4RS
4 Scavengers: A small group of orcs has set up an ambush here. They will try to stay hidden if opponents seem too tough or attack easy marks from hiding.

17) d12 roll: 7
Result: 2RL or 4ZM
4 Gnolls: A beleaguered group of gnolls is making their way back to camp. They will try to hide or flee if possible.

Room generation continues in that fashion until all 20 are detailed. If the area is cleared and given time to repopulate, another set of rolls on the same table can be used. These room descriptions aren’t terribly inspired. They rely heavily on your input but for quick and dirty filler they serve their purpose.

That’s all there is to using the 5 room dungeon templates and a few extra tables to create and fill a megadungeon. Though you will invariably want to add a good dose of GM fiat to things to make them more interesting and to add elements unaccounted for in the system, it’s an easy quick starting point and provides a solid base for modification.