Re: Ideas for Dungeon rooms and traps
The Map Trap
Sometimes your players need to learn not to blindly trust everything they're handed. This trap is designed for just such occasions. This is not a 'room' or static trap, but a psychological trap. The setup is that the characters are raiding the enemy stronghold. The nature of the stronghold depends on the game, naturally. It could be the evil villain's secret lair, or the skyscraper your shadowrunners are supposed to infiltrate, or the lich's necropolis. Regardless, getting from A to B is not a straight line, and without any idea where to go, the players are going to get taken down eventually. They need a map.
How they go about getting the map depends partly on your players, and partly on the genre. In a cyberpunk/sci-fi setting, the hacker can try and access the building schematics. In a fantasy setting, they can try and take out one of the guards to get information from him. Or perhaps there is a helpful map on the wall, like in the mall. Regardless, they find a map, and start looking for their destination. All's good, right?
Not exactly. See, the opposition leader in this case is just a bit paranoid and probably more than a little sadistic. You see, the map the players find is wrong. Oh, all the structural details are correct, but some of the rooms have been intentionally mislabeled. For instance, the room marked 'Main Control Room' will actually be the 'Basilisk feeding room', and 'Lunch Room C' will actually be a biological research lab. Meanwhile, the 'Auxiliary Trash Compactor' will be the Main Control Room.
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Hilarious Template Room
Sometimes, you want to throw an extra encounter at the party, but aren't quite sure what to do. In these situations, I like to take 'normal' monsters, and throw templates on them that will screw with players' heads. This is a tactic that can scale to any level, depending on the monsters used. For instance, say you have a tomb (or a necromantic research lab). You're going to expect undead, right? But few players expect to be attacked by a swarm of skeletal pixies. Scaling up a bit, a Half-Fiend Trumpet Archon or Half-Celestial Balor can make for one helluva story. And there's going to be one heckuva story behind that Half-fey Red Dragon. Again, this is less a 'room', and more a storytelling point.
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Dispel Magic Trap
A variant of the classic 'the door is trapped with a magic spell, and the rogue better have been searching for traps' ploy. While the normal use of a spell trap on a door is to blast the foolish person who wasn't checking for traps (or who failed to disarm the trap), this variant targets the floor. Specifically, the wall of force that was painted to look like the rest of the floor, and is hanging over a pit trap.