Monday, April 1, 2019

Underdark-Ocean Island Generator

Roll once for each category except intelligent inhabitants. 1 in 6 chance for an island to be inhabited. Here are some examples made by other people. You can also click a button to generate one easy from here. EDIT: This post has gotten very popular. Thanks everyone for the continued interest!

What are the waters surrounding the island like? - 1d8
[1] Unnaturally calm. Feeling of dread. Roll a random encounter.
[2] Stormy, spiked rocks. Ship's pilot makes a save or you take some hull damage.
[3] Filled with dark, spooky seaweed. If you fall overboard, they pull you down and drown you.
[4] Glowing- many deep sea like animals in a black coral reef.
[5] Filled with shipwrecks. Undead pirates of the undersea very likely.
[6] Well developed. Tons of range markers, buoys, shark nets and docks. If the island is inhabited, there is a steep dock fee. If the island is uninhabited, then this place is long abandoned.
[7] Playful pod of bone white, sickly looking dolphins. It's pretty cute, until you see them playing catch with a human skull using their tails.
[8] Getting there is easy- the sea is smooth and silent. But once you try to leave the island, fog rolls in and each time you burst through the fog you're back at the same island. It's cursed.

What is the Island made of? - 1d10
[1] Giant Fallen Stalactite. Very flat top, with tall cliffs to get up.
[2] Giant Stalagmite. Steep, mountainous island.
[3] Island of bones and insect shells; discarded for centuries as flotsam.
[4] Giant, bloated corpse of a leviathan. It will take an eon for it to be eaten away.
[5] Giant, sleeping cave olm. Hope it doesn't wake up.
[6] Frozen glacier. Magic black ice prevents it from melting.
[7] Artificial- stacked black bricks. Must have been a huge project.
[8] Artificial- huge petrified woods and stone columns stacked up. Created by underdark beavers- huge hollow interior chamber/dungeon very likely.
[9] Standard rocky island affair. However, small lake in center reveals eye of huge beast trapped inside the rock; the island is a prison for some primordial thing.
[10] Standard rocky island affair. Mushroom forest and lichen bog; very verdant for a place in the underdark. Elves probably lived here once.

What scary monster lives on this Island? - 1d10
[1] Not on the island, but in a cove with a hidden underwater cave. Aboleth.
[2] Fire Elemental. Lives at the top of a trapped “lighthouse”.
[3] Huge cave boar. Very blind, very angry. Still.
[4] Cave Olm. Has blue tattoos around its face, shoots lightning bolts.
[5] Immortal goblin, lives in his own filth. He's also totally invisible; slits throats with a giggle.
[6] Severed tentacle of some horror-beast. Sprays acid blood out the stub end.
[7] Dark-Elf Spellcaster. Very powerful, but water burns her like acid.
[8] Ogre Zombie, dressed head to toe in very thick armor. There's actually 1d8+1 of them, they're just all identically dressed, so rumors only ever speak of one.
[9] Living spell. Roll a random spell with any duration longer then instant, this spell is alive and permanent. Probably crazy, has abilities and attacks befitting the spell.
[10] Eyeless Beholder. It still has eyes on its stalks and can still see, it just considers itself blind because it lost its central eye. Banished for being a prick.

What other hazards are on the Island? - 1d10
[1] Mold spores. 1 in 4 chance every exploration turn to take a point of Con damage.
[2] Cold winds, enhanced by green-painted stone pillars. Take 1d6 Frost damage if the winds blow.
[3] Island's ground is notoriously unstable. Make a save or you fall through.
[4] Mouse traps, for dire mice. Deal 1d4 damage and take an exploration turn to pry each off.
[5] Poisonous berries and fruits, tainted fresh water. No chance for resupply.
[6] The island sinks every 1d3 days for half an hour; the residents know this. You don't.
[7] Undersea pirates use this place as a treasure stash. You can try to dig up buried treasure, but they've also buried explosive mines and undead-skeletons to attack pillagers.
[8] False Healers. They act as though they are healers, but lace bandages with glass shards and medicines are spiked with poisons. All “healing” they perform deals additional damage a turn later.
[9] There is a fairy grove on this island, unsual mushroom and lichen instead of trees and grass. But the fairies still play tricks on you, steal your map, make time pass faster, etc.
[10] Glass Dog. It's lonely, but every time it jumps or licks you it deals 1 damage cause it's made of glass. If you managed to catch it and bring it to the mage's guild you'll get a hefty reward.

What treasures are on the Island? - 1d12
[1] Skull of the last cave elephant. Regular elephants find it sacred.
[2] Magical, unbreakable elf rope. It's turned black over time, shouldn't be this strong.
[3] Corpse of a dwarf. Fell from the “sky” after digging too deep. Has chunks of platinum ore.
[4] Waterproof spellbook written in braille.
[5] Glow in the dark warhammer. Made of a marble-like stone. Would sink instantly in the sea.
[6] Pearl & Diamond Earring. The matching pair is lost at sea. Worth a few thousand gold.
[7] Magic Crossbow bolts, 1d4 of them in a sack. They light up as they fly, can be used as flares.
[8] Heart of a Lion. Wrapped up in eighteen layers of fabric. Useful magic reagent.
[9] A replacement sail. It has a pirate design; two mugs of ale smashing together with froth flying.
[10] Bag of a hundred silver coins. If you spend an exploration turn tapping coins, you have a 1 in 6 chance to find a fake coin that's actually gold underneath a silver paint. About 20 of them are fake.
[11] Magic warning sign. If a creature can read any language, then reading this sign forces them to make a morale check to proceed if they aren't in combat or chasing you or something.
[12] Water Nymph, trapped in a glass jar. She'll give you a kiss that will cure any disease if you bring her to a body of water on the surface. The underground sea is too dark and scary for her.

If inhabited; Who lives on the Island? - 1d6
[1] Dark Elves. They won't let you see them unless they know they can win a fight. Even to trade.
[2] Dwarf prospectors. They're marooned, and will pay for someone to ferry all 2d12 of them.
[3] Blue kobolds. Floppy ears. They're much smarter then your average kobold, and more sociable. One of them is going to stowaway on your ship for adventure.
[4] Medium sized town of Orcs, ~50 members of fighting age and skill. They hate it here and would much rather trade then fight any more annoying invaders.
[5] Almost-Humans. They are cave dwelling troglodyte creatures, who are slowly evolving to become human beings. Will pay handsomely for any corpses or human culture you can trade to them. They almost worship humans, but are clearly just an imitation working backwards.
[6] Underdark sea seal-people. They bask in the dark on the beaches here, never explored the interior. Only the alpha male has authority. He doesn't want anything you can offer, unless you can kill the bastard roving male that keeps trying to sneak onto my beach, please and thanks.


  1. Always in the mood for Sunless Sea.

  2. Nice tables, which I think would be useful with my procedural high seas hexcrawl:

    1. Thank you for including it on your blog! I also appreciated your math in that article; I'd use it if I was planning to run a more gritty, ocean-sailing adventure where tracking travel times and supplies like that would be central. It's a very useful resource!

  3. I wrote a post where I generate three islands using your tables. I thought it was very easy to use, and I like the results!

    1. I saw that post and followed it here :)! I may create an auto-generator for this table some time this week.

    2. Following up, I made the auto-generator! Will probably wait until later in the week to post. Please let me know if you don't want me to post it, or if you want to see it first, or anything like that.

    3. Feel free. I'll link it here when it's ready.

    4. Posted :)

  4. Awesome! I will probably hack this to run with monsters from the Pirates & Dragons rulebook & bestiary