20 Things to Find in a Subterranean River

Subterranean rivers often flow through natural caverns. Sometimes, they even intersect with dungeons. As a source of water—and therefore life—rivers and streams are often visiting by those dwelling nearby. Thus, there is almost always much to find near (or in) a subterranean river.

By Matt Morrow

By Matt Morrow


Use the table below, to determine what the PCs find in the river:

  1. A monstrous skull of some large, undoubtably ferocious creature lies at the bottom of the river, partially covered in silt. It lies wedged near the narrowest part of the water course.
  2. This river is surprisingly deep. At its deepest point, perceptive PCs spot what looks like a small cairn. Partially covered in silt it is completely submerged and looks like its been there for a long time.
  3. A bedraggled, ripped brown cloak is snagged between two large boulders. The sodden cloak is half in and half out of the water. It is cut for a halfling-sized creature (or perhaps a human child).
  4. The rusty hilt of a notched two-handed sword juts from the water. Any attempt to pull the sword from the water snaps the blade.
  5. A large stone has been dumped in the middle of the river to act as a stepping stone. Unfortunately, it is precariously balanced—unwary explorers will likely be dumped into the frigid water as the stone shifts unexpectedly underfoot.
  6. A school of tiny, albino fish live in the river. Constantly hungry, they swarm any potential source of food dumped in the river.
  7. Part of the riverbank has collapsed, partially damming the water course. The collapse has narrowed the river, and thus this is an easier place to cross.
  8. Several pieces of splintered wood—perhaps remnants of a spear’s haft—bob in the water.
  9. In this river, a stretch of water is discoloured by minerals in the rock; perceptive explorers spot a faint pink tint to the water. Paranoid explorers might suspect something—or someone—has recently bled into the river.
  10. A sunken rowboat, sodden rope still wrapped around a prominent rock on the bank, lies at the bottom of the river. One of the boat’s oars floats nearby, wedged among the rocks.
  11. Two abandoned crudely crafted wooden buckets stand on the river bank. One has been knocked over, but the other is full.
  12. Someone—or something—has cut a crude set of stone steps into the river bank where the river widens—and thus the water slows. A metal ring sunk into the wall provides evidence that once a boat was moored here.
  13. Crystals embedded in the river bank glimmer invitingly below the water when the PCs’ lights reach the area.
  14. Here, the river flows over a roughly man-high rock shelf into a wide pool before continuing onwards. The sound of the water tumbling into the pool is audible from quite some distance.
  15. Fronds growing from a great swath of lichen growing on the cavern roof dip down to the river’s surface, creating a curtain of sorts that those navigating the river must pass through to continue.
  16. The corpse of a bat twice the size of a normal specimen bobs up and down on the river as it is carried passed the party. Perceptive PCs notice the bat’s head has been ripped off.
  17. At this point, the cavern roof drops down almost to the surface of the water. Those in boats or on a raft must lie flat to proceed.
  18. A small channel burrows away from the river’s main course. A rusted portcullis blocks the small passageway and a profusion of small branches and other pieces of rubbish bob in the water before the portcullis.
  19. A line of rusting iron spikes about three-foot a part have been hammered into the river bank. There are sixty spikes in total and the last in the line trails a ten-foot long length of sodden rope.
  20. A thin crack in the ceiling lets a solitary beam of light play upon the river’s surface. The shimmering glimmer is noticeable from quite some distance. Perhaps subterranean predators have learnt the light often attracts prey, and already lurk nearby ready to pounce…

20 Things II_SNE_220This article will appear in GM’s Miscellany: 20 Things II, available in March 2017.

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