I’m looking at dungeons like they were video game levels.

Secrets are an important part of dungeon exploration. I’ve done a lot of research on level design in video games, and I’m applying what I’ve learned there to dungeon design. Every dungeon should have some secrets. In fact, every dungeon should probably have about the same number of secrets.

Why? Because you want players to look for them.

It’s important to establish a rapport with your players. They must have some expectations about your dungeon before you can begin to play with those expectations. What I figure for secrets is that you should have a number of secrets equal to about one-third the number of encounter areas.

If you have twelve encounter areas, that’s four secrets.

Secrets don’t have to be big and they don’t have to be really hard to find, either. They have to require the players to look for them, and they have to be there for players to find. If you don’t use secrets, players won’t know to look for them.

Where do you put the secrets? If you read my earlier post about doors, then you know that a good place to put one of your secrets — and the minimum number of secrets in a dungeon should be one — is behind a door. Generally not behind a locked door however, because a lock is a different kind of challenge.

That’s one secret, fine. What about the rest?

Good places to put secrets beyond the first are to evenly distribute them between empty encounter areas, and areas containing traps. A trap should generally be a clue to something being hidden nearby. Something important enough to be protected by a “round-the-clock” watch.

Here’s a hint about using traps and secrets in conjunction: do it. If the party doesn’t trigger a trap for whatever reason, they will surely trigger the trap by loitering around an area in order to search for secrets.

Just make sure to give them the reward afterward. They’ve earned it.

Empty areas are natural places to put secrets. Sometimes a hallway is just a hallway, but “in plain sight” is often one of the best ways to keep something hidden. There might be a few valuable gems embedded in a mural amid the detritus — the key here is to have some features in each encounter area.

Every dungeon should have some useless junk, too. One monster’s trash is an adventurer’s treasure, as they say — or maybe I made that one up myself.

The trick is to keep it even, placing equal numbers of secrets among “blank” encounter areas and those containing traps. Only rarely do you want to put a secret in a room containing a monster or other encounter.

This is important because you want to allow players to perform “pacifist” or “stealth” runs, and it isn’t sporting to force them into fights.