Gnomish Submarine Free Multi-Level TTRPG Battlemap with Adventure

They Wait Below

While at a port, you see a large group of dwarves hauling a strange looking ship up out of the water using a giant crane. The ship is unlike any you’ve ever seen, being fully-enclosed with a large sphere of glass built into its hull, which makes up at least a 3rd of it. The strange vessel appears damaged however, and if you ask any of the bystanding dwarves about it, the dwarf you’re speaking to shakes his head and says that they’ve invented a new type of vessel–one which can travel under the water, not above it. Only thing is, none of the ones they’ve sent out have returned. Just this one.

When the submarine floated to the surface a few knots out from the docks, the dwarf explains, just one member of the crew was left on it. Everyone else was just… gone. And the survivor who sailed it back was stark, raving mad. They couldn’t get a word of sense out of him. They’re taking the submarine in for repairs, but they’re going to need to send her back out again when she’s fixed to figure out what happened and try to reclaim the missing vessels–otherwise his years of hard work and family’s inheritance will have been wasted for nothing. He can’t allow that to happen. If they can just figure out what in the bloody hells is going on, his invention will do the world a lot of good.

If you ask him what he means, he explains that he’s the dwarf who designed the vessels, and it’s his business which is about to fail. He then catches himself, and introduces himself as Svet, shaking your hand. He seems to look at you properly for the first time, and observes that you’re a mercenary, before asking if you might be willing to go down with his men once the vessel’s repaired, to keep them safe in case things go amiss. He doesn’t have terribly much gold left after he sunk it all into this new venture, but he says he has enough to pay you well for your efforts.

Should you agree, he thanks you, before saying to meet him back here several days hence to head out. In the meantime, he suggests you speak with the survivor of the last venture, in case he’s recovered enough to talk some sense. His name is Val, and he’s being cared for at the local church.

When you get to the church and ask after Val, the nuns there lead you to a locked room. Inside it is the dwarf, sitting in a bed curled in a ball, rocking back and forth and mumbling to himself in a language you don’t know and no-one else seems to know, either. The sound of it gives you shivers on your skin, and feels… wrong. His hands are both bound in bandages, and there are strange symbols written on the walls in blood. They make you feel dizzy looking at them.

Val refuses to acknowledge your presence, and looks through you. Just as you give up to leave, he looks you straight in the eye and warns you that the darkness is alive. Should you ask what he means, he goes back into his dazed state and begins speaking the weird language again.

Once you set out on the submarine, despite the repairs you can make out strange sentences in an unknown language written in blood on the walls similar to what were in Val’s room. It’s stained the timber and, despite all their attempts to clean them off, the words couldn’t be removed.

As the ship descends with you and the dwarven crew, following the path of the submarines which went missing, the sea grows dark around you. After several hours travelling deeper and deeper into the darkest depths of the sea, you begin to hear loud groaning noises from outside the submarine, as if large creatures are swimming by–but if you try to look out from the glass interior you can’t see anything.

Shortly afterwards, the lights on the vessel start flickering off and on again. The few dwarves in your section (the rest are elsewhere on the submarine) start getting nervous, while some among them become paranoid and claim they’re hearing something whispering–can’t you hear it?

You catch movement out of the corner of your eye beyond the glass, and can see dark shapes moving off in the distance in the water. Soon after one of the dwarves yells in fear, claiming they saw a face outside the ship.

At this point, the flickering lights go out completely, and the submarine stops moving. Nothing wants to work if you try to engage the magic again. There is a noise at the back of the ship, as of something entering through the airlock. But if you move through the still-dark submarine to inspect it, some of the dwarves who were meant to be stationed nearby there have gone missing. You also find some bloodstains, drag marks, as well as a couple of bodies which have been mauled to death brutally, with claws and bite wounds that look like some kind of animal.

You hear screams from elsewhere in the submarine, and if you rush towards them you find a monstrous fish-man standing over the bodies. It has large, bulbous eyes, scaly skin, a terribly toothy maw, as well as poisonous spines all over it. It attacks using its teeth and claws, until it’s injured, at which point it shoots spines at you from its hands while attempting to flee into the air vents.

There are five of the creatures on the ship in total. They kidnapping or murdering those who are too difficult to drag out into the dark abyss.

When you kill the last monster, as it dies it says something in that strange, terrible language the mad dwarf Val was raving.

Once all the monsters are dead, the lights flicker back on and the ship’s engine begins whirring again. In front of the submarine, scattered across the sea floor, are all the other submarine wrecks. Amidst them you see the shadows of creatures the size of dwarves…

GM’s Notes:

R’lyehian is the language Val speaks, and it’s also what’s written on the walls of the submarine. The monsters your players encounter are Deep Ones.

Whoever hears the dying words of the last Deep One begins getting unsettling dreams every night, which involve darkness and great, malevolent tentacles in primordial muck. The dreams slowly grow more and more disturbing the longer they plague their victim; eventually a voice within the visions beckons the dreamer to “come to me”.

Once the lights are on again in the ship, your players might notice that there are fresh symbols on the walls, which some of the dwarves who claimed to hear whispering appear to have written in their own blood.

If you’d enjoy way more TTRPG battlemaps with adventures like this free one, Luke and I have just released our newest bundle of 420 large, 40×30″ battlemaps (double the size of those in the Quarantine Bundle) for $59.99. It’s your chance to have a great deal on some of our most beautiful maps! We guarantee that is something here for every GM—no matter what setting you prefer, from large cities to underwater seascapes.

Paying just $59.99 rather than full price saves you over 97%! Take a look at all the extra maps you can download with one click here.