Optimum number of rooms for a dungeon?

Person in Electric Bastionland???

It’s seven. Plus or minus two.

Where are my psychology people at?

Yeah, that’s the optimized number of things you can hold in your head at one time.

Why would you want to hold the layout of a dungeon in your and your players’ heads?

If you either don’t have the brainpower or patience to map it out. Me, all the time.

(Yes, I got spurned by BX/OSE’s tedious mapping protocols, but that’s a story for another time.)

7±2 rooms is the perfect number for the GM and the players, helping everyone keep a good grasp on what’s been already visited in the dungeon without getting lost.

“But Sam, haven’t you run The Waking of Willowby Hall? That has over two dozen rooms!”

Yes, but I throw an unkeyed map at the players every time. I call it the “Your uncle left you a cool-looking map of a nearby abandoned mansion. It’s dangerous to go alone, here take this.” hook.

But for natural, unmapped places of the world? Wildernesses? The Underground?

Yeah, no.

I’m not (totally) against mapping. I’m against all things that slow the game down, melt my brain, and increase the odds of me just throwing random encounters at the party until they quit asking me for room dimensions.

Back to the number of rooms. George Miller figured this one out in 1957.


So, 5 to 9.

The boundaries of your day job is 9 to 5, the boundaries of your night job is 5 to 9.

Whatever helps you remember when you sit down and get out your pencil, graph paper, and copy of Maze Rats.

Need an example?

Belly of the Fishy Beast is 8 rooms and I’ve got the whole dungeon memorized. Also, every time I run it, at least two rooms get totally bypassed. There is a “golden path” of sorts, but objectives can be encountered out of order.

Five is the number of rooms that Johann Four advocates for. I read this book from him (free) after totally forgetting about this structure of dungeon design.


  1. Entrance and Guardian
  2. Puzzle or Role-Playing Challenge
  3. Trick or Setback Complex
  4. Climax Big boss fight
  5. Reward, Revelation, Plot Twist

In that order.

Every time?

Isn’t that a little dry? Perhaps.

(Here are some alternate layouts for those interested)

The (current) Cheap, No-Visuals, Five Room Dungeon Dragonslayer Way

(warning, lots of links that could put you down a dungeon design rabbit hole)

Get out a textpad. No visuals.

Five rooms down the line.






Follow the order of “Entrance” then “Puzzle” then “Trick” etc from above. (Read the first 20-ish pages Johann’s book to get an idea of the thinking behind this)

Theming is good. Introduce elements in the initial rooms and then mix them together in one or more later rooms. (Chris McDowall has an EXCELLENT post on this).

Make the exits/hallways between each room somewhat interesting. Locks, odd methods of transportation, gates (READ THIS from the Angry GM).

Now, five is the minimum, both of a five room dungeon format and the “7±2 rule.” You can always add more.

Make one or more offshoots. Give choice, but keep the golden path of the five rooms. Bonus points if it loops (READ THIS about why you should loop stuff). Note these by making a “B” option. For example, a room that veers from room 3 would be “3B.”

Make one area (any area) an abstract area. This is where you can MASSIVELY expand the dungeon either through some improv or with later planning. Things like cities (Stomach City from Belly of the Fishy Beast above), wilderness areas, mazes, large buildings. What’s cool with these is that you can just make a list of options here (stores, encounters, events, discoveries, dangers) and roll with that.

Important to note that “rooms” ain’t just rooms. Johann explains some of that in the book. Whatever the players encounter that prompts a choice, that’s your room.

You could make this nonsense on a napkin.

Psssst… You can cheat off my homework

I’ve been making and remaking some adventures for my Outschool class.

If you like digging through the muck of un-refinement, here. I originally ran this in a game of Electric Bastionland, so it’s a wee bit gonzo:

Jailhouse Heist

“Fenson” (sweaty, heavy-breathing guard, Dennis Nedry from Jurassic Park, takes inhaler a worrying number of times) wants revenge for being fired from the prison, but can’t go in or else he’ll be recognized. “You can keep the money, just put them under. But don’t for the love of Pete say it was me.”

1) Outside the Fence

  • Long line of cars, drivers are sleeping out of boredom. They’re paid by the hour and are totally okay with being held up and taking a nap.
    • In the back of one car are three prisoners, playing rock, paper, scissors. What are the stakes?
    • In another, many many prisoner uniforms.
    • Last one, an absurd amount of water bottles.
  • “Bogey” (Bear mockery, Bobo from The Muppets, sniffles, dumb as a box of rocks, just wants to help) is at the gate control, but doesn’t know which button to hit (OPEN or CLOSE). He keeps hitting CLOSE even when told otherwise. He’s terrified of seeming stupid, incompetent, or fire-able.

2) Prison – Front Courtyard

  • Buzzing lamplights (very bright, murderous fireflies, potential explosion hazard)
  • Parking garage (rusty cars and Chomper (large digging machine, keys aren’t here))
  • Tool Shed (tool belts (3), uniforms, flashlights, smokebomb, stun baton)
  • Exit: One guard waiting at the building entrance. Want to see some ID.

3) “Welcome” Desk

  • “Chet” (smoker woman voice, beefy tattooed clerk). Insists you fill out paperwork, wait in the waiting room so they don’t have to deal with you, or both. “Paperwork” is a bunch of meaningless scribbles on huge stacks of paper. The real trick is not filling out the paperwork, but getting Chet to like you enough to let you through. Showing contempt for “the system”, complimenting looks, or offering food gives a “looks like everything checks out” regardless of quality or quantity. Like most bureaucracy, it’s all arbitrary. 😉
  • Exits: Side waiting room and the prison hallway.

3B) Waiting Room

  • Chairs, magazines, pictures of overly happy prisoners, nervous soon-to-be inmate

4) Prison Hallway + Cells.

  • Abstract area. Roll d6 and cross off that option. Skip that option when rolling again. Or just do the encounters as they interest you or as time permits/demands.
  1. “Clean up on aisle 12!”
  2. Storage closet (broom, mop, mechanicals)
  3. Slug monster that acid projectile vomits on the floor in front of its cell.
  4. “Tott” Shady cleric guy “I used to be an adventurer like you once. Come ‘ere, I’ll tell you a story.” Betrayed by a party member in the last fight of a dungeon with a gelatinous cube. Advice: “Never trust anyone.”
  5. Fleshman monstrosity, worriedly trying to escape his prison cell. Disgusting amount of fat and skin.
  6. Cafe area filled with prisoners and guards. One dwarf loudly shouts a challenge.
  7. Steam guard bot on the fritz. Demands that you return to your cell. Clearly not working. Content to handcuff you to a chair. Sprays oil.
  8. Two pushy steam guard bots demand identification.
  9. Three guards acting out a prisoner escape out of boredom.
  10. Two guards talking through one guy’s relationship problems. He got ghosted. Found her with another guy. “How can I get her back?” Second guard to players: “how rude, can’t you see the guy is in pain?”
  11. Warden (strict, Tarkin-like), showing an inspector around with six guards. LOOK ALIVE!
  12. Grand Office (Lockbox of all the $$$ behind the painting of the “happiest prison ever”).
  13. Warden’s Office (keys to everything here including all doors and Chomper)

5) The Escape

  • “Stuff” hits the fan, just like in every good heist. Chases? Explosions? Angry beefy clerks?
  • If “Bogey” is at the gate still, he’ll smash that “CLOSE” button to secure the escape of those “nice people,” regardless of how nice or mean they were. He just doesn’t want to make anyone mad.

Yay! Silly fun dungeon!

Now make your own!

(Of whatever variety, doesn’t have to be silly fun)

11 thoughts on “Optimum number of rooms for a dungeon?

  1. I find a good layout is a 3 by 3 grid. Start the players in one corner, put their goal in the other. 9 rooms, with a golden path of 5 and 6 (I think) paths the party can take without backtracking.
    If the players feel like backtracking, there’s more rooms to explore.

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