A “dungeon” is any place where monsters and treasures may be found. A dungeon is usually a group of rooms, connected by corridors. It could be a castle (new or ruined), some caves, or anything else you can imagine. Check out our blog post on 4 types of dungeons

The “level” of a dungeon is a number that identifies part of the dungeon and usually indicates the amount of danger present in that area of the dungeon. Level One, or the “first level,” is usually the place where the smallest monsters and treasures can be found. Level 2 is usually more dangerous than level 1, and as the numbers increase, so does the danger. A dungeon may have any number of levels.

A good dungeon is reasonable. Its design is carefully thought out, and the monsters and treasures are placed for a reason. Even a random dungeon layout could be good if the monsters within it were selected and placed carefully. For example, randomly drawn caves would give a disorganized design of rooms and corridors, but could be a good dungeon if occupied only by cave dwellers, such as animals (normal and giant) and human-like monster tribes (such as goblins).

Location Seeds

  • A network of natural caves beneath an ancient hollowed-out tree
  • A long-forgotten cellar beneath an inn
  • A field of ruin in the corpse of a massive dragon
  • A mad wizard’s trapped dungeon
  • Festering sewers beneath the city
  • A fortress carved from a stone mountain
  • A haunted catacombs in a mound carved like a giant skull
  • A forgotten crypt of a mad king
  • A temple of an evil cult hidden in the chambers of a church
  • The remains of a city buried under volcanic rock

Draw the Map

Click to get Dungeon Journal Pages

Using graph paper and pencil, draw a map of the dungeon. First, select a scale. The scale of a map is the number of feet (length and area) represented by one square on the paper. A common scale is “1 square = 5’ x 5’ area.” For outdoor areas, like the town mentioned above, a 20’ x 20’ map square is common.

Second, draw the overall shape of the dungeon, based on the setting. For caves, no exact shape is needed; you could simply draw a line for the outer edge, break it with a few entrances, and fill the rest of the map paper with rooms and corridors. For a tower, however, you must decide on a size and shape before continuing.

Some sections of the map may be left blank, to be filled in later.


Stock the Dungeon

Dungeon Checklist – use this list to inspire you to build more than just a Hack and Slash adventure!

  1. Something to Steal
  2. Something to Kill
  3. Something to Kill You
  4. Different Paths
  5. Someone to Talk To
  6. Something to Experiment With
  7. Something the party probably won’t find
  8. Environment Hazards
  9. Puzzle / Trick / Role Playing Challenge
  10. One thing that makes no sense at all

When building your adventure think about the overall ecology of the location. Would it make sense for certain monsters to exist together or specify types of monsters (like Undead)? Would they fight each other? Do they have a symbiotic relationship? Where do they eat? sleep? poop? Does the orc tribe have goblin servants? Is it a combat encounter or filled with dangerous traps?


Why are we adventuring? Check out the Designing Adventures page for how to setup the story of your dungeon.

Creating Encounters

Encounters are the heartbeat of any adventure, providing a dynamic framework where storytelling and strategy intertwine. Whether the players are negotiating with a territorial dragon, outwitting a cunning band of thieves, or uncovering the secrets of an ancient ruin, it’s essential to design encounters that offer a rich tapestry of outcomes, with combat being just one of many possible avenues.

To create these encounters, start by considering the objectives and motivations of the beings the players might meet. Examine the experience value (XP) of each potential adversary or ally, as this can guide you in balancing the encounter’s challenge. Take the combined total levels of the player characters and multiply it by 50 to establish a baseline for the encounter’s complexity. Remember, this is merely a starting point and a guide. As the Dungeon Master, you have the flexibility to adjust the encounter’s difficulty by varying the number and nature of the creatures or characters involved.

It’s important to note that perfectly balancing each encounter should not be the ultimate goal. In the unpredictable world of adventure, players may face situations that are overwhelmingly dangerous and potentially lead to a Total Party Kill (TPK). Such encounters can underscore the risks of adventuring and encourage players to think creatively about how to handle various threats beyond direct confrontation.

Encounters should challenge players not just with the threat of combat, but also with opportunities for diplomacy, deception, and problem-solving. Each interaction can pivot on the players’ choices and creativity, leading to a multitude of outcomes that enrich the narrative and deepen the gameplay experience.

Wandering monsters add an additional layer of unpredictability to your encounter design. These creatures or entities are not tied to a specific location and can appear at any moment, often catching players off guard. Including wandering monsters can enhance the sense of a living, breathing world where danger and discovery lurk around every corner. To integrate these effectively, consider using random encounter tables that reflect the environment the players are exploring.

The unpredictability of wandering monsters forces players to adapt on the fly, promoting resourcefulness and strategic thinking. These encounters can serve as unexpected interruptions that shift the narrative and test the party’s ability to handle sudden challenges. Whether a wandering monster becomes an immediate threat, a potential ally, or a mysterious figure with its own agenda, these dynamic encounters can significantly enrich the adventuring experience.


Four 1st level characters ( 4 x 50 = 200 xp encounter) should get a good work out against 20 goblins. On the other hand, a Hill Giant (1200 xp) would completely destroy the entire party if it was encountered.


A trap is anything that could cause damage, delay players, or trigger a magical effect to occur. The trap may be found, and possibly removed, by a thief character using their Disarm Traps ability. Traps may be placed on doors, walls, ceilings, room furnishings (tables, chests, etc.), or directly on a treasure. You may combine traps, or place several in one area, but try not to make the encounter too dangerous for the characters. Deadly traps are not recommended until the 2nd level of a dungeon (or deeper) is reached.

Some typical traps:

Blade: A blade sweeps out, down, or up, hitting someone (possibly allowing a Dexterity Save) for damage.

Creature: A monster (snake, beetle, spider, etc.) jumps up and gets 1 free attack by surprise.

Darts: Some tiny darts, shot by a spring mechanism, shoot out and hit someone (either automatic hits or by making Hit Rolls), for damage or some other effect (paralysis, poison, curse, etc.).

Explosion: Something blows up, causing damage to everyone in the area in any set amount or dice range, but a Wisdom Save should allow damage to be reduced to half unless the explosion is an illusion.

Falling Items: A block (or rubble) falls when something is touched (or at random), striking someone and allowing a Dexterity Save (DC17) for trying to jump out of the way for damage (either a given number or a dice range).

Fog: Looks like poison gas, but a failed Wisdom Save results in (pick one): nothing, giggles, fear, a terrible smell for 1-6 turns (which may attract monsters or increase Wandering Monster chances), anger (victims attack each other for 1-4 rounds; a Wisdom Save may be applied), or paralysis.

Illusion: Something strange happens (but not really; see Phantasmal Force, a magic-users spell), and the characters may be scared away (or the illusion may have some other effect, such as giving a false clue, luring characters toward another trap, etc.).

Light: A bright light flashes, and all seeing it are blinded for a time (a Wisdom Save should apply, possibly with a bonus or penalty to the roll).

Pit: A section of the floor gives way, and (one, some, or all) characters fall in, taking (ld4, ld6, ld8, ld10) damage. The pit may have something at the bottom (spikes for more damage, deep water, or a monster). It could be a chute, leading down (a oneway ride) to the next dungeon level.

Poison Gas: Victims make Constitution Save or take damage (ld4, ld6, or whatever is dangerous but not deadly to most characters). Additionally, a Constitution Save with bonuses(+1,+2,+ 4 ) to the roll may be made, with failure meaning death. Gas is usually in a container, released when opened.

Poison Needle: This is a small needle, hidden somewhere and nearly undetectable until accidentally touched when it will spring out and poke a character who tries to open something.

Special Encounters

A “special” is anything you place that is not normal, but is not a trap, monster, or treasure. Some typical specials are:

Alarm: Summons a special monster, opens dungeon doors, or has no effect at all.

Falling: Falling characters or monsters take 1d6 damage per 10 feet dropped. Dexterity Save for half damage.

Gelatinous Cube: This monster (AC 10, HP 24) is made of clear jelly, usually in the form of a 10 x 10 x 10-foot cube (though other shapes are possible). It is hard to see, and it surprises often (+13). A gelatinous cube moves through the rooms and corridors of a dungeon, sweeping the halls clean of all living and dead material. In the process, it may pick up items it cannot dissolve (such as weapons, coins, and gems). It will attack any living creature it encounters. Any successful hit will paralyze the victim unless a Constitution Save is made. An attack on a paralyzed victim will automatically hit (only a damage roll is needed). This paralysis is the normal type (lasting 2-8 turns unless magically cured). A gelatinous cube may be harmed by fire and weapons, but not by cold or lightning.

Green Slime: Green slime cannot be harmed by any attacks except fire or cold. It dissolves cloth or leather instantly, wood and metal in 6 rounds, but cannot dissolve stone. Green slime often clings to walls and ceilings and drops down by surprise. Once in contact with flesh, it sticks and turns the flesh into green slime. It cannot be scraped off but maybe burnt off (or treated with a Cure Disease spell). When green slime drops on a victim (or is stepped on), the victim can usually burn it while it dissolves armor and clothing. If it is not burned off, the victim will turn completely into green slime 1-4 rounds after the first 6-round (one minute) period. Burning does 1/2 damage to the green slime and 1/2 damage to the victim.

Illusion: A dungeon feature (stairs, room, door, monster, treasure, etc.) is not really there, but is merely a phantasm.

Lurker / Trapper: These creatures resemble a giant, flattened manta ray made of stone that blends into the dungeon floor, making it very difficult to see in shadows. Glowing lichen under its body casts flickering light.

Stats: AC 10 (they’re hard), Hit Dice 4 (24 Hit points).

Two variations have evolved specialized hunting strategies:

Lurker: Floats near the ceiling and ambushes from above.

Trapper: Lies on the floor and ambushes from below.

Spotting the Creatures:
Only with a DC 18 Notice or Search check will adventurers spot the lurker or trapper before an ambush.

Ambush Attack:
If not spotted beforehand, the creature’s edges will suddenly close around the adventurers like a drawstring bag, completely enveloping them while excreting a corrosive acid. Those who are enveloped take 1d8 acid damage perpetually until the acid is removed (DC 10 Wisdom check). Any nonmagical equipment becomes worthless after 3 failed DC 10 saves.

Map Change: A shifting wall moves after the party passes, cutting off their exit. They must find another way out of the dungeon. The wall shifts back after a time (1 turn, 1 hour, 1 day).

Movement: The room (or stairs, or door, or item) moves (turns, drops, closes, rises, etc.) unexpectedly. As the DM you may allow a DC check to notice the change and possibly do something about it, such as diving out of the room.

Pool: Magical water has a strange effect if touched (or drunk, or sprinkled on someone or something), such as healing, inflicting damage, changing an Ability Score, changing Alignment, making something magical for a time, invisible for a time, etc.

Sounds: The room (or item, or treasure) makes strange noises: moaning, screaming, talking, etc.

Statue: A large statue of a person, monster, or gadget (nearly anything you can imagine) is found. It may be valuable, magical, too heavy to move, alive, lonesome and willing to talk (maybe a liar), covering a trap door down, a treasure, etc.

Transportation: This could be a trap door leading up or down, secret stairs, an elevator, a magical portal to elsewhere (another room, another level, another dungeon), etc.

Trick Monster: This applies to any variation of a listed monster, such as a skeleton that shoots its fingertips like a Magic Missile, a two-headed giant ogre, a “goop” dragon that spits green slime or grey ooze, a wild bore (a shaggy man who tells long, dreary stories), a quarterling (half-sized halfling), a Mouth Harpy (who can’t sing but plays the harmonica), an Ogre Jelly (looks like an ogre, but . . .) Rock and Roll Baboon, and so forth.

Weird Things: You may let your imagination run, placing such things as weapons that fly attacking by themselves, talking skulls, a magic item or treasure firmly stuck to the floor (or wall, or ceiling), a magical area (zero gravity, reversed gravity, growth to double size, shrink to 1” tall; effect lasts until leaving the area), a huge creature recently slain (too big to fit through the corridors get here?”), and so forth.

Yellow Mold: This deadly fungus covers an area of 10 square feet (“one” for No. Appearing), though many may be found together. Yellow mold can only be killed by fire: a torch will do 1d4 points of damage to it each round. It can eat through wood and leather but cannot harm metal or stone. It does not attack, but if it is touched, even by a torch, the touch may (50% chance per touch) cause the mold to squirt out a 10’ x 10’ x 10’ cloud of spores. Anyone caught within the cloud will take 1-6 points of damage and must make a Constitution Save or choke to death within 6 rounds.

Additional Reading

A Guide to Utilizing Slimes, Puddings, and Molds in Encounters

Encountering Monsters

Wandering Monsters Level Up Your Dungeon Game

Encounter Design: Why Challenge Ratings Don’t Tell the Whole Story (and Why Your Players Will Thank You)

A Comprehensive Role-Playing Game Encounter Guide

Railroading Players: Striking a Balance Between Story and Agency

Breathing Life into Your Dungeons

Making Sure Everyone Gets a Turn: How to Be Heard in Your Game


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