Ruin Logic

What should I put in my ruin? a GM asks on Facebook. The question is smarter than it might appear. If you are aiming for an immersive, coherent world and an exciting adventure, it can be tough to stock a ruin properly.

Throw stuff in randomly and you might find yourself on the defensive or retconning as players try to make sense of its ecology. Or, worse, they might make reasonable, fatal errors because they expected the dungeon to make some kind of sense that it didn’t in fact make. It may be helpful to think of the ruin as having three or four sections:

the Grounds (the area around the ruin),

the Landmark (the visible part of the ruin that’s easily explored and already well-spoiled by previous visitors),

the Sanctum (a hidden and/or well-secured area that the PCs will be the first to visit),

and, optionally, the Intersect (a place where the site intersects with tunnels or underground realms, creating an opening through which denizens of the Underdark might enter the complex).

 

The Grounds 

Grounds refers to the landscape or terrain immediately around (and possibly influenced by) the ruin. Because any ruin offers an historical and geographic landmark, and because the people who built it probably did other things in the vicinity, it’s best to think of the zone outside of the ruin as the first encounter area.

Other constructions. Perhaps there are remnants of old roads, or old markers, or vine-covered statues, or crumbling bridges, or ancient aqueducts near the site.

Surrounding terrain. Terrain can help set the tone before the adventurers ever set foot in the complex. For a richer sense of terrain, mix together several types. Wetlands with forests (swamps, bayous) can feel very different from coastal wetlands (salt marshes), which can feel quite different from mires (wetlands with acidic peat). Hills can be forested and rounded; they can be tall and barren; or they can be low and stony — just an expanse of gently rolling limestone, like Ireland’s Burren karst, pictured below.

You can spark your creativity for terrain by rolling (1d10) two or more times on this terrain table:

1. Arctic
2. Coastal
3. Desert
4. Forest
5. Grasslands
6. Hill
7. Mountain
8. Swamp
9. Ocean/Island (example: Ocean + Desert might be a desert island)
10. Underground (example: Karst might be seen as a splice of underground and plains or underground and hills, as it tends to be cave-riddled and represents what the earth looks like when the topsoil is removed.)

Here’s another landscape tip: Remember that geography is fractal. When you see maps or photos of terrain, imagine changing their scale way up or way down. You could take a photo of muddy puddles in your yard and scale it up to represent an entire swamp. You could take a topographic map of the Rocky Mountains and scale it down, treating it as a single battlefield along a less-impressive ridge.

Local people. Any local people probably have some sort of historic relationship with the builders — perhaps their ancestors were the builders’ slaves at one point, or perhaps they are descended from the builders, or perhaps they are invaders who displaced the builders.

Lair effects. Even if the occupants you imagine for the site don’t have Lair Effects listed in the Monster Manual (see the book’s entry on Lair Effects), you might consider attaching some kind of Lair Effect to the ruin. By way of one example, the entire realm of Ravenloft might be said to have pronounced Lair Effects.

Apex predators. If the ruin is the lair of a major, active, monstrous threat that can roam freely, the grounds might be strangely quiet and full of foreboding. But if any threats within the ruin are well-constrained, then the Grounds might easily be occupied or patrolled by third parties or wild animals.

The Landmark

Crumbling castle walls. A sundered tower. Stone stairs that lead to something that is no longer there. Flagstones, once the floor of some large chamber, now exposed to sun, wind, rain.

The landmark is the visible, exposed, open part of the ruin. It is also, probably, the element that most games goof up — even though, ironically, it’s also the element with which GMs probably have the most real-world experience, unless they have never been tourists.

Too often, GMs start springing traps and guardians immediately — but then one has to wonder how all of those immediate defenses are maintained, healed, repaired, or replaced, because surely they must have been imperiling travelers and curious kids for centuries. No, in most cases, the obvious parts of the ruins will already be fully explored, and any guardians or defenses once there have been fully triggered and no longer pose much threat.

Ah, you say, but now the ruin is boring.

Not necessarily.

First off, the landmark provides a great opportunity for building atmosphere: the PCs find the bones of a long-dead dragon, a pit trap filled with mud and silt due to past flooding, a few sprung and rusted traps, shattered forms of once-moving statues, all with bugs and weeds thriving around them. Nothing foreshadows doom better than scenes of the dead and ruined. And some of those discoveries might be clues that the PCs need to have in order to succeed later. So don’t skip this part!

Secondly, “no guardians” doesn’t mean no danger. The landmark can be very dangerous. The site might now be the lair of an above-ground monster or a group of humanoids. The builders never planned on them and they aren’t “guardians” of whatever lies below, but they’re still a potential threat. In addition, the landmark — being exposed to the elements — is likely overrun with unintelligent life of some sort. It might feature slimes, molds, hungry vegetation, rabid rats, nests of vipers, or insect swarms. Any local apex predator might very well have scars from encounters with such mindless hazards and stay well away from them, since they cannot easily be intimidated.

Furthermore, most ruins will have originally been built of stone and wood, and the wood will likely have decayed and rotted away, leaving stonework that may not be as well supported as it once was. Rooms that once were boring and safe may now have unstable structures, and stairs and landings might now be missing, forcing PCs to scale walls to get from one room to the next. Unless doors are made of sturdy stuff, they are probably also rotted away, along with tapestries, rugs, and the like. Add to this the fact that the ground has likely shifted over the centuries due to earthquakes, volcanic activity, and the occasional passing purple worm, and you get an unguarded ruin that is still quite dangerous.

Want more? Ruins and underground areas may sometimes accumulate toxic or inflammable gases, or release gases when objects are shifted. Methane, firedamp, histoplasmosis and other airborne threats — including any made-up for fun by a diabolical GM — can be particularly challenging because they don’t have ACs or hit points.

Hazards can even combine or compound each other: Stepping on a poorly supported stone block might drop someone into a pit (where once there had been wooden stairs). The falling PC might land in a carpet of aggressive fungus or mold, triggering a spore explosion (and possibly nausea or hallucinations). And if you’re really diabolical, the local hobgoblins using the site as a camp might decide to make their attack as the PCs are trying to deal with the pit and fungus threat, forcing everyone to fight around the hazards.

In short, landmarks don’t have to be boring. But they should exhibit few remaining signs of builder intent. Even ancient messages in the form of glyphs, markings, frescoes, mosaics, and the like may be faded or chipped away in these areas.

The Sanctum

If the ruin is going to be worth exploring, it should probably have an area that no one has explored before. I refer to this area as the sanctum, in part because the builders have often taken extra precautions to keep people out of it.

Most often, they have done this by being sneaky or clever. After all, a large door advertising the wealth of a kingdom behind it is going to get knocked on a lot over the centuries. At some point, someone will have succeeded in exploring all of the obvious stuff. That leaves the non-obvious.

Also, hiding a sanctum is cheaper and more efficient than trying to come up with guardians so bad-ass that no one can get through them. The builders will have almost certainly employed most or all of the following strategies for hiding the area:

1. Secret or concealed doors. Like the door into Erebor.
2. Misdirection and red herrings, causing people to dig in the wrong places. As with the Nazis and the Lost Ark.
3. False doors and false tombs.

As an alternative, sometimes an area might be cut off from explorers by accident rather than by design. For instance, flood and erosion and collapse of upper levels or above-ground structures can, over time, hide openings that once might have been obvious. An expedition might literally have to dig to get to the good stuff below.

The real trick for the GM, though, is how to ensure the PCs succeed where everyone else has failed. How do they find the hidden sanctum? One tried-and-true technique (used by Gandalf!) is to have them obtain a unique map or document, that, when taken with clues found at the scene, offers them just enough information to get the job done.

Note that if a divination spell (like augury) can easily lead the party the right way, then some other spellcaster will have probably already looted the place. Divination might help, in other words, but it shouldn’t do all of the work in this scenario. By way of example, suppose that clues lead the adventurers to a chamber with not one but three secret doors. They need to choose the right one. Augury might help with that choice, but they should need some unique tool to get to that decision point.

That unique tool doesn’t have to be a map. It might even enable divination spells to work when normally they wouldn’t. For instance, maybe the PCs acquire an orb. Let’s call that orb the Sanctum Key. The Sanctum Key never appears to do anything. It doesn’t have a map; it doesn’t point to anything. However, if anyone casts divination or commune or legend lore to learn where the sanctum is, the spell fails unless they’re holding the orb. That way, spellcasters are still rewarded for taking divination spells. At the same time, the GM gets to preserve the sense that no one could have ever reached the same area before. (It sucks to prepare divination spells and then have GMs refuse to let them work. But just as creatures can be fire-resistant or resistant to nonmagical weaponry, an area might be divination-resistant without being divination-proof. Resistant is more fun.)

Once the party is into the sanctum area, you can go Tomb of Horrors crazy. Assume any traps in here are still primed. If they’re magical, they might not need much maintenance or “reloading.” Barring earthquakes, any sanctum guardians are likely undamaged.

Ah, but what kinds of guardians should prowl the sanctum? They’ve been sealed down here for centuries or millennia perhaps. What types of monsters would still be “ticking”? The obvious contenders are nonliving things: golems, undead, animated objects. Other options exist, however: summoning traps might bring in elementals or fiends; others might release well-preserved monsters from stasis or from a mirror of life-trapping. A fun one-time option (never to be re-used) is to use something like a mirror of opposition or domination or simulacrum trap that pits the PCs against each other or against facsimiles of themselves. That way, they bring their encounters in with them. (Note that you shouldn’t use the magical mirrors I’ve listed above unless you’re prepared for PCs to carry them around and use them. They’re epic items and should probably be reserved for epic ruins.)

The Intersect (optional)

Sometimes when you dig down, you meet someone else digging up. Similarly, the passageways under a ruin may have, over time, come to intersect with the burrowings of intelligent or unintelligent creatures from the Underdark. If you decide this has happened, try to ensure the intersection doesn’t happen within the Sanctum — unless you want to include a plot twist in which grimlocks have burrowed in beneath the supposedly impregnable, secret treasure room and stolen the treasure. (Of course, if they have, that might lead to a fun sequel adventure in the grimlock tunnels.) If the sanctum remains unspoiled, however, then any intersect should meet up with the landmark or the grounds, not the sanctum.

To decide what is in the intersect area, simply look again at the landmark and grounds guidance above — for from the perspective of the Underdark, the landmark of the ruin is poking into their world, and about it are grounds that may be deeply affected by that fact. ♜

♦ Graham Robert Scott writes regularly for Ludus Ludorum when not teaching or writing scholarly stuff. Graham has also written a Dungeon Magazine city adventure titled “Thirds of Purloined Vellum” and a fantasy novella titled Godfathom. Like the Ludus on Facebook to get a heads-up when we publish new content.