The prison map generator draws a stone gaol on five-foot squares. You come in through a gatehouse in the front wall, past a portcullis, into a service corridor that runs the width of the building. Ahead is the guard station, a desk with the keys on it, and beyond it the main corridor runs the length of the cell block. The cells line both sides, twelve to twenty of them, each with a straw pallet and a bucket, and their fronts are drawn as bars so you can see who's inside; about four in ten are occupied. Braziers burn at each end of the corridor. Across the block from the guard station, a passage leads out to the exercise yard behind the high back wall, with a well and either a scaffold or a whipping post. Along the front are four rooms: the guard room and the warden's office on either side of the gate, and two more drawn from an interrogation room, a mess hall, an armoury and a row of solitary pits. Every area is numbered and keyed.
How the prison is laid out
The plan works the way a gaol has to. There's one way in, through the gatehouse, and every route from a cell to the outside passes the guard station. The cells face each other across the corridor so a single guard can watch them all. The front rooms open onto the service corridor rather than straight onto the cells, so prisoners never pass the armoury or the warden's office. The yard is enclosed by the outer wall on three sides and the cell block on the fourth.
Each roll changes the depth of the yard, the size of the cells and which rooms stand at the front. The guard room has a table for dice and a rack of keys on hooks. The warden's office has a desk with papers, a strongbox and a rug. The interrogation room has a chair, a brazier and a bench of tools. The mess hall has long tables and a cook pot, the armoury has weapon racks, and the solitary pits are three round holes with iron grates over them.
Breaking in, breaking out
Prisons are one of the most common set pieces in a campaign: a friend has been arrested, a witness is locked up, or the party wakes up in a cell. The layout gives every version something to work with. Breaking out means getting past the bars, the guard station and the gatehouse, or over the yard wall. Breaking in means the gate, the wall, or a guard who can be bought. The warden's office is where the records are, the armoury is where the party's gear ended up, and the solitary pits are where someone important is being kept out of sight.
Free SVG and PNG downloads
Both formats are free for your games, streams and published adventures. The PNG is a 1920-pixel render ready for Roll20, Foundry or Owlbear Rodeo, and the Print button gives you a black-and-white sheet for the table. The SVG is the vector original: open it in Inkscape, Affinity or Figma to fill or empty cells, add a tunnel or move the armoury. 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 the ground floor of one prison. It doesn't draw the town around it, a second floor of cells or the sewers underneath. For an escape route under the walls, roll a sewer map; for the dungeon cells under a castle, a castle or dungeon map.
Name the prisoners and the warden
The villain name generator names the warden, the rogue name generator names whoever is planning the escape, and the guild name generator names the gang that's paying for it.