This is a quick tutorial covering the steps I take when laying out and drawing a cave map.
1. Get the map layout right with simple shapes
Dungeons are flow charts. Use simple shapes to figure out where players come in, where they go, how they can bypass certain obstacles, and choke points they need to go through. Don’t worry about pretty at this stage, and use pencil. You should be sketching and changing a lot. This is mapmaking as adventure design.
This can take 5 minutes or this can take days.
2. Use pen to draw in rough cave walls
You know where the walls are now so you can go in with pen and layout jagged dungeon walls. Break up the shapes from before – turn the caves into odd shapes. Never let your pen fly along the edge of the cavern, make it walk like a drunken sailor, creating a meandering jagged line.
3. Add detail lines inside the cave wall
When we see a hard line designating a wall, we mentally visualise a vertical wall and a horizontal floor. That’s not true in caves – so I add details along the wall edge to show the rough jagged transition of an organic cave into the floor. For built maps I’d add the detail in the wall instead, because you want that visual cue of a clean corner, but not here.
And you’re done!