Draw and stock three levels of your dungeon.

“Step 3 [...] is very difficult and time consuming. Each level should have a central theme and some distinguishing feature, i.e. a level with large open areas swarming with goblins, one where the basic pattern of corridors seems to repeat endlessly, one inhabited by nothing but fire-dwelling or fire-using monsters, etc. As each level is finished the various means of getting to lower levels must be keyed and noted on the appropriate lower levels [...] A careful plan of what monsters and treasures will be found where on each level is also most necessary, and it can take as long to prepare as the level itself.” – EGG

Tasks

• [ ] Describe the entrance to the dungeon in 7-10 words. You can tell a lot about a place by looking at its doors.
• [ ] Create a point-to-point map. This is a simple map with circles (rooms, caves, etc.) that are connected to each other by lines (passages, tunnels, halls, stairs, slides...). Don’t worry about visuals just yet, this map will help you create a good flow for the dungeon. You can add scale and detail later.
• [ ] You will draw three levels. For each level, include at least d6+6 rooms/areas and connect them. Make sure they aren’t connected like a string of pearls (all in a line). At least half the rooms should have more than one way in/out. Add more rooms if you need ‘em!
• [ ] Include several (say d3+1) ways up and/or down per level. These exits may double-count, e.g. a stairs down on level 1 is also the stairs up on level 2 and/or level 3. Remember that it doesn’t have to be stairs: you can use slides, shafts, elevators, rivers, etc.
• [ ] Come up with 1 theme per level. Try rolling d3+2 for each theme to generate a sort of budget. This will help you remember to reinforce the themes multiple times each level. (Unlike a real budget, it’s okay to over-spend!) Example themes: tomb raiders, spiders, machines, fountains and pools, or fungi. As you stock the dungeon you will spend your budget to incorporate references to your themes via ornamentation, creatures, sensory details, etc. It is okay for a theme to “spill over” into the level above or below.
• [ ] Make a list of about a dozen iconic monsters and place them in rooms/areas. You can put them in rooms or passages, and on any level. Generally, the more dangerous the creature the lower it will be found. If any of the monsters help sell one of your themes, remember to reduce the budget accordingly. Your monsters could also be arranged in a 2d6 wandering monster table. Put the ones most likely to roam around in the middle of the table.
• [ ] Spread d6 major features throughout the dungeon. Features should be interactive: traps, puzzles, talking doors, magic fountains... If any of them reinforce a theme, reduce its budget. These are features that are unique or notable. Fill in around these features with general “dungeon dressing” as needed. If you roll a small number, make each feature really impactful!
• [ ] For each room/area, note any treasure. Roll a d6 for each are. If it contains a creature or feature, there is treasure on a 1-4. Otherwise, there is treasure only on a 1. If you have random treasure tables, you can go ahead and roll up each of these piles of treasure now to save time later.
• [ ] Name three wondrous items and locate them in the dungeon. Pull them from your source material or make them up. Again, if they reinforce a theme, you can reduce that theme’s budget. These are probably in addition to any magic items that get rolled up as part of placed treasure, unless you rolled some really good ones.
• [ ] Spend any remaining theme budget adding detail. Note unusual smells, weird lighting, odd stonework, statues or other decorative elements, disturbing noises, messages written on the wall, corpses of previous adventurers...

Extra Credit

• [ ] Map out all three levels on graph paper. Gygax would say this is an imperative, but in “theater of the mind” style games it may not be necessary. The old school scale for maps is 1:10’ (ten foot squares), which will allow you to fit a lot more dungeon on a page, but you can go 1:5’ if you like or if you plan on running a more tactical game. If you don’t map it out on graph paper, make some notes on your bubbles and lines about ceiling height, lengths of corridors, sizes and shapes of rooms, etc. Enough for a good description.

  

Example