Empty rooms? Boring, right?
Wrong. Not every room needs to have a monster, trap, or treasure. If that were the case then you'll never get your players through the dungeon before Gamer ADD kicks in and you start hankering to play one of those new-fangled games like Fiasco or Microscope... or Risus.
No, what you need is a handy D30 table to add just a little bit of zing to what would otherwise be scenery. Something to trigger your player's latent paranoia and perhaps something that can plant the seeds for real encounters down the road.
- Nothing that can be fought (or at least nothing that can fight back)
- Nothing that is remotely valuable (except perhaps to the most enterprising of player characters)
- Nothing more dangerous than an inconvenience (not counting unforeseen consequences).
D30* EMPTY ROOM TABLE
- Disputed territory. The room has been fought over by rival denizens. Look for contradictory graffiti and signs of past struggles. Characters seen entering or leaving (wearing the wrong colors) may be accused of being allied to the rival faction.
- Remains of dead adventurer. Roll up a random NPC, don't bother to give him any gear (it's all been looted), kill him, and leave his mutilated body lying on the floor (or hanging from the ceiling or whatever). There is a 2 in 6 chance his spirit lingers, but it has been so traumatized this it will prove useless to interrogate.
- Localized weather pattern. Roll 1d4: 1) cold spot, 2) circular air current, 3) indistinct vapors, 4) increased humidity (leading to spontaneous condensation).
- Crawling with vermin. The vermin are harmless but the party can still be scared into needless and silly precautions. Roll 1d8: 1) flies, 2) beetles, 3) cockroaches, 4) centipedes, 5) rats, 6) snakes, 7) stink bugs, 8) worms.
- Bats (and bat guano)! Mostly harmless but may fly to other rooms and possibly put out torches when they are disturbed.
- Ectoplasmic residue. Looks like boogers (or bogeys if you speak English with an English accent).
- Aspected mana. If you are not a Gurps nerd then this means that certain magic is slightly more effective here. I like to occasionally throw in spontaneous effects as well. Roll 1d8: 1) Light spells, 2) Necromancy, 3) Healing, 4) Fire, 5) Earth, 6) Summoning, 7) Water/Acid, 8) Divination.
- Gratuitous NPC reference. Go back over your list of NPCs that haven't come up in a while. Assuming that the NPC is "Bob", roll a d4: 1) Graffitti with "Bob was here."; 2) Bob's recently deceased corpse (see item #2); 3) an encrypted letter bearing Bob's seal; 4) Bob's signet ring/diplomatic credentials/passport/driver's license.
- Unexplained scorch marks. Couldn't be spontaneous combustion, could it?
- Alchemical residue. Roll on your favorite potion table and apply the effect only if a curious player character licks it or shoves it up their nose (or other orifice). The effect is transitory and will desert the player just as they are about to use it for something useful.
- Strange fungus. As #10 but the effect is a hallucination.
- Bloodstains. 1 in 6 chance that "Help Me!" is written in blood.
- Rock cairn. Who builds these things?
- Patrol route. Check for wandering monsters every time characters enter the room.
- Dimly glowing green rock. Harmless unless you have been dying to introduce mutations into your game.
- Disgusting odor. Rol 1d6: 1) vomit, 2) poop, 3) rotting corpse, 4) cat piss, 5) old socks, 6) cheap perfume.
- Poop. Not just the odor this time.
- Weird Magnetic field. Makes your lodestone go crazy and may induce alien abduction hallucinations.
- Phosphorescent lichen. Noticeable only in the dark. Roll 1d6: on 1 it leads to a room with a particularly nice stash of loot; on 2 it leads straight into a trap.
- Social disease. Adventurers should be careful about where they do their business.
- Really awesome graffiti. Perhaps from a misunderstood kobold that the party just killed. Too bad he'll never get a chance to go to art school.
- Debris. Broken, pottery, rocks, bits of glass, etc. Impossible to sneak up on anything if there were anything worth sneaking up on. The footing also kind of sucks if there is ever a fight here.
- Cobwebs. Lots of them. They are the regular kind, which is especially weird if your exploring lava tubes or caverns made out of ice.
- Victim. Like #2 but obviously not an adventurer. An innocent from a nearby village if you are feeling nasty, that grouch of an inn keeper if you are a softy.
- Blue slime. It jiggles menacingly.
- Humming. Actually, the faint sound of someone humming. The worst part is that it is that stupid song that all the bards are playing these days that you just can't get out of your gods-damned head.
- Crumbs of what must have been a really delicious meal of elvish way bread. It's hard tack for you suckers.
- Temporal anomaly. Time passes ten times faster inside this room.
- Holy ground. Well, it would be holy if any of the characters worshiped Hakuna the Obscure. He'd listen to your prayers if you had any.
- Meta-dream room. Characters who sleep in this room gain visions of a group of friends playing games around a table. The strangest part is that they are talking about the character and his adventures.
* Ignore last 10 entries if you lack the approrpriate gamer paraphernalia.
Note that proper old school modules will come pre-loaded with empty rooms (I refer you to the Empty Room Principle). Some of these rooms are great for placing your own encounters but even then, some of them will remain empty. Feel free to use the Empty Room table to add a tiny but of mystery to those rooms without bogging down the dungeon.