The swamp map generator draws a marsh encounter site on five-foot squares, the kind of place where the water hides what's in it. The ground is a patchwork of dry hummocks, shallow water and deep pools, traced from a noise field so the shorelines wander the way real wetland does. Reeds crowd the edges of the water, dead trees stand on the higher ground, and a plank boardwalk crosses the whole sheet from one side to the other. Out in the shallows there's a hut on stilts, a stone statue is sinking in the deepest water, and on one patch of dry land somebody has laid a ring of bones and candles. Every point of interest is numbered and keyed.
How the swamp is drawn
The water comes from a single field of smooth noise. The lowest quarter of it is deep water, drawn dark, and the next quarter is shallows; the rest is mud and grass. Because the field is continuous, the deep pools sit inside the shallows the way they do in a real marsh, and the outlines are traced smoothly rather than stepped along the grid.
On top of that the swamp gets its landmarks. The boardwalk is the one safe route across, laid edge to edge with every plank drawn. The stilt hut goes in shallow water away from the boardwalk, so getting to it means wading. The statue goes in deep water, with only its head above the surface. The hag's circle needs dry land and goes on a hummock away from everything else. The deepest point of the deepest pool is marked too, because something lives there.
Terrain that fights back
A swamp is a hard place to fight, which is the point. Shallow water is difficult terrain, deep water means swimming, and the reeds give cover to anything small enough to hide in them. The boardwalk is narrow and the only fast way across, so it's where an ambush happens and where a fight turns into a shoving match. Dead trees give a little cover and a lot of atmosphere.
Using it at the table
Use it for a lizardfolk ambush, a hag's lair, a lost patrol, or the crossing the party has to make to reach the ruin on the far side. It suits any fantasy game on a grid, D&D 5e and Pathfinder included. Decide who lives in the stilt hut, what the circle was for and what's at the bottom of the deep pool, and the encounter writes itself.
Free SVG and PNG downloads
Both formats are free for your games, streams and published adventures. The PNG is a 1920-pixel render for a VTT, and the Print button saves a black-and-white version for a home printer. The SVG is the original vector file: open it in Inkscape, Affinity or Figma to break a section of the boardwalk, add a second hut or rename the pool. Everything on the map is drawn by our own code, so there's no attribution to carry and no asset licence to read.
What it won't do
It draws one swamp encounter site. It doesn't draw a whole marsh region, the inside of the stilt hut, or what's under the water. For the region, roll a hex map; for the lair beneath, a cave map.
Name the swamp, then cross it
The swamp name generator gives the marsh a name and a history, and draws this same map beside its result. The witch name generator names whoever drew the circle. For other wild places, try the forest map generator and the desert map generator.