"There is a cloud of inky black darkness"
Tables for Combat Terrain and Minor Treasures and Encounter Complications for Underwater Encounters. Result is from Underwater Encounter Complications.
Enhancements by terrain - arctic | coastal | desert | forest | grassland | hill | mountain | swamp | underdark | underwater | urban
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Underwater Encounter Enhancements
What makes this underwater encounter different?
There might be a whale skeleton or an area of grasping seaweed. A creature might carry several holy symbols of sea deities or a bead of force. There might be several underwater cave entrances or a hallucinator terrain concealing a chasm.
There is a 5e Underwater random encounter generator at ChaosGen. There is also a pdf of these and more tables at the DM's Guild as Underwater Encounters.
Underwater - encs 2024 | encs 2014 | locs | noncombat | extras | all underwater
Underwater Combat Terrain
| 1d8+1d12 | Underwater Combat Terrain |
|---|---|
| 2 | A maelstrom |
| 3 | Bottom of a cliff |
| 4 | An area of magical darkness |
| 5 | A cave entrance blocked sticky seaweed (treat as webbing - DMG pg 105) |
| 6 | A whale skeleton |
| 7 | A floating pocket of air |
| 8 | A column of stone |
| 9 | A glyph of warding (explosive runes - thunder) |
| 10 | A cage on a chain or half of a wreched ship |
| 11 | Grasping seaweed in the area acts as an entangle spell |
| 12 | A swarm of inquisitive brightly-colored fish, attracted to any light source |
| 13 | A strong current runs through the area |
| 14 | An underwater cave entrance |
| 15 | A cloud of inky black darkness |
| 16 | A forceful current pulls creatures downwards |
| 17 | An anchor with a chain leading upwards |
| 18 | A deep trench |
| 19 | A forceful current pulls creatures upwards |
| 20 | A hidden cache (Perception check to spot if near) with oil of slipperiness (or roll on Minor Underwater Treasures) |
Underwater Minor Treasures
| 1d20 | Underwater Minor Treasures |
|---|---|
| 2 | A large green peridot worth 1000 gp |
| 3 | Potion of Storm Giant Strength or Potion of Vitality |
| 4 | Intricate set of dragonchess with ivory pieces using creatures of the sea |
| 5 | Elemental Gem (water) |
| 6 | Several sheets of bronze engraved with sea elf ballads in Elven |
| 7 | Elixir of Health or Potion of Greater Healing |
| 8 | A long reed pipe covered in runes in Aquan and intricate carvings of seahorses. Worth 150 gp |
| 9 | Potion of Animal Friendship or Scroll of Protection - Beast |
| 10 | An exotic saddle or 100 ft. of silk rope |
| 11 | 1d4 Potions of Water Breathing or 1d4 Potions of Healing |
| 12 | Artisan's tools (mason's tools or alchemist's supplies) |
| 13 | Oil of Slipperiness |
| 14 | 2d6 holy symbols of various sea deities |
| 15 | Spell Scroll of control water (or freedom of movement) |
| 16 | 2d4 waterproof ceramic and glass lanterns capable of working underwater. Worth 50 gp each |
| 17 | Bead of Force or Dust of Dryness |
| 18 | 1d6 pearls worth 100 gp each |
| 19 | Spell Scroll of mirage arcana (or telepathy) |
| 20 | A hooded cloak with eight tentacles. It is finely woven of rare seaweed and sea-elf hair. Worth 1200 gp |
Underwater Encounter Complications
| 1d8+1d12 | Underwater Encounter Complications |
|---|---|
| 2 | There is a programmed illusion (or mirage arcana) here |
| 3 | There are merrow (or roll on Underwater Humanoids) here (or nearby) as allies (or servants / mercenaries) |
| 4 | There is a hallucinatory terrain concealing a chasm |
| 5 | There is a cloud of inky black darkness or roll on Underwater Combat Terrain |
| 6 | There is a hidden item (or cache) here. A Bead of Force or roll on Minor Underwater Treasures |
| 7 | There is a whale skeleton or roll on Underwater Combat Terrain |
| 8 | There are giant sea horses here (or nearby) as pets (or guards). For alternatives roll on Underwater Beasts |
| 9 | There is a strong current running through the area or roll on Underwater Combat Terrain |
| 10 | There is a prisoner in the encounter or a lone traveler nearby. Roll on Quick Underwater NPCs |
| 11 | There is a wreck here (or ancient sunken settlement) |
| 12 | The creatures are carrying a magic item (or it is hidden nearby). Roll on Magic Items - Underwater |
| 13 | There is a floating pocket of air or roll on Underwater Hazards and Obstacles |
| 14 | There are several underwater cave entrances here |
| 15 | There is a swarm of inquisitive seahorses or roll on Underwater Hazards & Obstacles |
| 16 | Nearby is a dragon turtle (or pick from Underwater Encounters Level 11+) those encountered try not to disturb. |
| 17 | There mass of rotting bodies chained together or roll on Underwater Hazards and Obstacles |
| 18 | There is a portal here to the Elemental Plane of Water (or the river Styx in the Lower Planes) |
| 19 | There is a second group of creatures nearby (roll again on the appropriate encounter table) |
| 20 | There is a shrine to a sea deity protected by hallow (or forbiddance) |
More Encounters
There is a 5e Underwater random encounter generator at ChaosGen. There is also a pdf of these and more tables at the DM's Guild as Underwater Encounters.
If you liked these there are D&D Generators at Chaos Gen, a monthly random tools Newsletter and an instagram of Random Tables.

