Subterranean River Battle Map - Launch (Patreon)

Hello Adventurers! Here is our second map of the month, the Subterranean River! I can’t imagine anything finer than a nice boat trip down a dark underground river with the odd roper and swarm of Stirges to spice up the journey! This map could be used as a single encounter where the players enter the map from the tunnel or they could be travelling by boat and of course, something is bound to be attracted to those juicy adventurers :D

Our final map of the month will be launched next weekend and will be an urban map called Hangman’s Square. I imagine it's a grubby part of town with a few market stalls and vendors selling souvenirs. Crowds gather here to watch the macabre (and free) entertainment.

As always I want to thank you all for your support, creating these maps is a rather time-consuming job and without you, it simply wouldn’t be possible. I hope you have a wonderful and productive week to come and as always happy adventuring! Now grab those oars and start rowing!

By all means rotate the map 90 degrees, it may work better for you on screen!

Introduction

You huddle together on the raft as it drifts through the flooded tunnel. The water flows slowly, barely making a sound as it meanders through the subterranean passage. Once in a while, you pass a small waterfall, little more than a trickle running down the glistening rock walls. Water occasionally drips from the tunnel’s roof, making small bell-like chimes that echo into the shadows that surround you. Bioluminescent fungus grows from the walls and ceiling, its soft blue glow reminiscent of starlight as it reflects off the water's surface. Time seems to move differently here, you are unsure how long you've traveled this waterway, a few hours, maybe a day, it's difficult to tell. Ahead you begin to hear another sound, a leathery flapping of small wings. The rest of your party hear it too, they look around nervously, their shifting weight making the raft rock slightly. You continue to drift forward, rounding a bend in the river and into a large open chamber.

The river laps against a grey-green shore to the right, what could be described as a beach leading up to a dark tunnel entrance in the rock wall. To the left rises a cliff with dozens of small openings, from those openings fly tiny creatures, darting across the cave to the tunnel on the opposite side and vanishing from view. Stalactites hang from the roof of the cave in clusters, crystallized fingers of minerals formed over eons.

With lightning speed, a whip-like appendage shoots from a stalactite and grabs a creature from the air. In moments the appendage is retracted and the creature, flapping feebly, is consumed. One of your party hisses under their breath “Ropers”. With horror you look up just as another appendage shoots towards you, hearing a dull thud you look down to see a purple-green tentacle attached firmly to the edge of the raft. You barely have enough time to grab your weapons before the raft is launched into the air, throwing you and your party into the icy water.

Hints and Tips

• 30x30 Grid map
• I very much like the idea that dungeons and cave systems have a realistic ecology, things eating other things. In this case, Stirges or some other flying creature are eaten by Ropers.
• I’ve added a Raft asset to the downloads.
• This could be a place where Underdark NPCs come to collect eggs from some nesting creatures. Have your party agree to collect eggs for a reward or information. What type of eggs? Well… something with teeth or fangs, claws, suckers, you know the drill.
• Stirges are always a fun low-level monster to throw at your party. If you have a lot of them, group them up for ease of play.
• Cave Fishers are a good alternative for Ropers. They are crab-like, human-sized creatures that use very sticky silk-like filaments to entangle prey.
• A cult could be using this as a place to sacrifice victims. They tie up someone and leave the ‘creatures in the walls’ to devour them.
• The river doesn’t need to be that deep, your party could walk along it to get somewhere, obviously, this will reduce their speed and may pose more environmental effects due to the cold or maybe the quality of the water… also leeches!

Variants

Everyone gets a cute little raft!

Need a desert river? Here is a day and night version for you!

How about something for Icewind Dale? A frosty/snow version