Appendix A: Random Dungeons
Source: Dungeon Master’s Guide (2014), p. 290
This appendix helps you quickly generate a dungeon. The tables work in an iterative manner. First, roll a starting area, then roll to determine the passages and doors found in that area. One you have initial passages and doors, determine the location and nature of subsequent passages, doors, chambers, stairs, and so on-each of them generated by rolls on different tables.
Following these instructions can lead to sprawling complexes that more than fill a single sheet of graph paper. If you want to constrain the dungeon, establish limits ahead of time on how far it can grow. The most obvious limit to a dungeon’s size is the graph paper it’s drawn on. If a feature would exceed the boundaries of the page, curtail it. A corridor might turn or come to a dead end at the map’s edge, or you can make a chamber smaller to fit the available space.
Alternatively, you can decide that passages leading off the edge of the map are additional dungeon entrances. Stairs, shafts, and other features that would normally lead to levels you don’t plan to map can serve a similar purpose.
Starting Area
The Starting Area table produces a chamber or a set of corridors at the entrance to your dungeon. When rolling for a random starting area, pick one of the doors or passages leading into the starting area as the entrance to the dungeon as a whole.
Once you’ve selected the entrance, roll on the appropriate table for each passage or door leading away from the starting area. Passages each extend 10 feet beyond the starting area. After that point, check on the Passage table for each passage to determine what lies beyond. Use the Beyond a Door table to determine what lies behind doors and secret doors.
Passages
When generating passages and corridors, roll on the Passage table multiple times, extending the length and branches of any open passage on the map until you arrive at a door or chamber.
Whenever you create a new passage, roll to determine its width. If the passage branches from another passage, roll a d12 on the Passage Width table. If it comes from a chamber, roll a d20 on that table, but the width of the passage must be at least 5 feet smaller than the longest dimension of the chamber.
Doors
Whenever a table roll indicates a door, roll on the Door Type table to determine its nature, then roll on the Beyond a Door table to see what lies on the other side of it. If a door is barred, you decide which side of the door the bar is on. Unlocked doors can also be stuck, at your discretion. See chapter 5, “Adventure Environments,” for information on doors and portcullises.
Chambers
Whenever a roll on a table indicates a chamber, use the Chamber table to define its dimensions. Then roll on the Chamber Exits table to determine the number of exits. For each exit, roll on the Exit Location and Exit Type tables to determine the nature and placement of the exit.
Use the tables in the “Stocking a Dungeon” section to determine the contents of a chamber.
Stairs
Stairs can include any means of going up and down, including ramps, chimneys, open shafts, elevators, and ladders. If your dungeon has more than one level, the amount of space between levels is up to you. A distance of 30 feet works fine for most dungeons.
Connecting Areas
When your map is done, consider adding doors between chambers and passages that are next to each other but otherwise not connected. Such doors create more paths through the dungeon and expand players’ options.
If your dungeon consists of more than one level, be sure that any stairs, pits, and other vertical passages line up between levels. If you’re using graph paper, lay a new page on top of your existing map, mark the locations of stairs and other features shared by the two levels, and begin mapping the new level.
Stocking a Dungeon
Creating a map for your dungeon is only half the fun. Once you have the layout, you need to decide what challenges and rewards are to be found in the dungeon’s passages and chambers. Any reasonably large space should be stocked with interesting sights, sounds, objects, and creatures.
You don’t need to have every last detail of your dungeon plotted out. You can get by with nothing more than a list of monsters, a list of treasures, and a list of one or two key elements for each dungeon area.
Chamber Purpose
A room’s purpose can help determine its furnishings and other contents.
For each chamber on your dungeon map, establish its purpose or use the tables below to generate ideas. Each type of dungeon described in the “Dungeon Purpose” section of chapter 5, “Adventure Environments,” has its own table featuring chambers geared to the dungeon’s purpose. For example, if you’re building a tomb, use the Dungeon: Tomb table to help you determine the purpose of each chamber. These dungeon-specific tables are followed by the General Dungeon Chambers table, which you can use if your dungeon isn’t an exact fit for one of the standard types of dungeon or if you want to mix things up.
Relying on random rolls to stock an entire dungeon can lead to incongruous results. A tiny room might end up being identified as a temple, while the huge chamber next door serves as storage. It can be fun to try to make sense of such strange design ideas, but make changes as you see fit. You can set aside a few key rooms and create specific contents for them.
Current Chamber State
If a dungeon has a tumultuous history, you can roll to determine the current condition of any particular area. Otherwise, if the room is still used for its intended purpose, it remains intact.
Chamber Contents
Once you have a sense of the purpose of the various dungeon chambers, you can think about the contents of those areas. The Dungeon Chamber Contents table allows you to randomly roll contents for a chamber, or you can choose contents for specific areas. If you choose contents, be sure to include an interesting, colorful assortment of things. In addition to the contents shown on this table, refer to “Dungeon Dressing” later in this appendix for additional items and elements to fill rooms.
In the Dungeon Chamber Contents table, a “dominant inhabitant” is a creature that controls an area. Pets and allied creatures are subservient to the dominant inhabitant. “Random creatures” are scavengers or nuisances, usually lone monsters or small groups passing through the area. They include such creatures as carrion crawlers, dire rats, gelatinous cubes, and rust monsters. See chapter 3, “Creating Adventures,” for more information on random encounters.
Monsters and Motivations
See chapter 3, “Creating Adventures,” for guidance on creating encounters with monsters. To foster variety and suspense, be sure to include encounters of varying difficulty.
A powerful creature encountered early in the dungeon sets an exciting tone and forces the adventurers to rely on their wits. For example, an ancient red dragon might slumber on the first level of a dungeon, a pall of smoke and the sound of its heavy breathing filling the chambers near its lair. Clever characters will do their utmost to avoid the dragon, even as the party’s brave thief makes off with a few coins from its hoard.
Not all monsters are automatically hostile. When placing monsters in your dungeon, consider their relationships to nearby creatures and their attitudes toward adventurers. Characters might be able to appease a hungry beast by offering it food, and smarter creatures have complex motivations. The Monster Motivation table lets you use a monster’s goals to define its presence in the dungeon.
For large groups of monsters encountered across multiple chambers, motivation could apply to the entire group, or each subgroup could have conflicting goals.
Random Dungeon Hazards
Hazards are rarely found in inhabited areas, because monsters either clear them away or avoid them. Shriekers and violet fungi are described in the Monster Manual. The other hazards on the table are described in chapter 5, “Adventure Environments.”
Random Obstacles
Obstacles block progress through the dungeon. In some cases, what adventurers consider an obstacle is an easy path for the dungeon’s inhabitants. For example, a flooded chamber is a barrier to many characters but easily navigated by water-breathing creatures.
Obstacles can affect more than one room. A chasm might run through several passages and chambers, or send cracks through the stonework in a wider area around it. An area of battering winds that emanates from a magic altar could stir the air less dangerously for hundreds of feet in all directions.
Random Traps
If you need a trap quickly or want to drop random traps into a dungeon, use the sample traps presented in chapter 5, “Adventure Environments” or the tables below. If you use the tables, start with the Trap Effects and Trap Trigger tables to decide the type of trap, then use the Trap Damage Severity tables to decide how deadly it should be. For more information on trap damage severity, see chapter 5.
Random Tricks
Tricks are quirkier and less deadly than traps. Some are effects left behind by the dungeon’s creators, while others might be manifestations of the strange magical energy suffusing the dungeon.
The following tables allow you to generate random tricks. Roll first to determine an object that the trick is placed on, then roll to determine the nature of the trick. Some tricks are permanent effects that can’t be dispelled; others are temporary or can be neutralized with a dispel magic spell. You decide which is which.
Random treasures
Use the tables and guidelines in chapter 7, “Treasure” to determine the treasure in each area of your dungeon.
Empty Rooms
An empty room can be a godsend for characters who need a safe place to take a short rest. Characters can also barricade themselves there and take a long rest.
Sometimes such a room isn’t as empty as it appears. If the characters search a room carefully, you can reward them with a secret compartment containing a journal belonging to a previous inhabitant, a map leading to another dungeon, or some other discovery.
Dungeon Dressing
The tables in this section provide miscellaneous items and points of interest that can be placed in your dungeon. Dungeon dressing can help establish the atmosphere of a dungeon, give clues about its creators and history, provide the basis for tricks and traps, or encourage exploration.
To generate dungeon dressing at random, roll once on each of the following tables: Noises, Air, and Odors. Roll as often as you like on the other tables in this section, or choose appropriate furnishings for the area.