I once wrote an adventure designed around a trap-filled dungeon called the Magekiller; it had been built by a wizard named Arrogan as a secure place to store his treasure. There were traps all over the place - that was the whole point of the dungeon - but one I particularly liked involved a straight corridor. The whole Magekiller complex was underground, with eight-foot-tall ceilings. Down a long stretch of straight tunnel (of the standard 5-foot width) there was an area with a 25-foot-diameter circle carved out of the surrounding stone, with the circle's center in the middle of the corridor. So narrow tunnel, wider circular chamber, and then narrow tunnel again on the opposite side. Inside the circular chamber was a metal cylinder, of a diameter a mere few inches smaller than the surrounding circular chamber. This metal cylinder was 7 feet tall, and all along the bottom were triangular gaps, spaced right next to each other, so the whole thing stood upon the tips of these points, like a saw. Finally, there was one normal-sized doorway cut into this cylinder; when the PCs encountered it the doorway was facing north, the direction from which they approached.
Once inside the cylinder, they noticed several things. First of all, there were seven metal bars sticking out from the interior sides of the cylinder, each about two feet long and pointing towards the center; had there not been a doorway cut into the cylinder, there would likely have been an eighth bar there as well. And finally, since they could see through the triangular holes at the bottom of the cylinder, they saw there was nothing but rock walls on all sides - except for directly across the cylinder from the doorway they had entered. So the solution seemed simple: everybody grabbed a bar and pushed the cylinder counterclockwise for half a circuit until the "doorway" in the cylinder lined up with the doorway to the south of the circular chamber.
This was accomplished, quite slowly and noisily (for the metal tips of the cylinder were dragging across the stone floor), but the wizard cast a grease beneath the metal tips of the cylinder and that helped. Still, it took a good half minute or more to get the cylinder repositioned so the PCs could travel down the southern corridor and see if they could find Arrogan's treasure. The corridor led to another circular room, this one containing an old, unworking fountain filled with what looked like brackish, algae-covered water. However, the "water" was actually an arcane ooze, which poured itself out of the fountain and attacked - not only with its acidic body, but also by "stealing" spells directly from the minds of the spellcasters, which not only lessened their spellcasting repertoire but healed the ooze. The PCs were forced to flee, back into the circular chamber with the metal cylinder, where they knew it'd take a good half minute to reposition the "doorway" back to the north (and that was with all six of them struggling at the task)...and in the meantime, the arcane ooze had no trouble at all sliding through the triangular openings along the bottom of the metal cylinder and into the chamber with those tasty morsels.... Eventually, the PCs had to forego any attempts at escape out of the dead end of their own making and concentrate on killing the arcane ooze before it killed them.
This trap didn't kill any of the PCs but it came pretty close, and after they had finally slain the arcane ooze they decided they were done messing about in the Magekiller for the day, opting to camp out where they were and not go wandering around any further to set off any other traps when they were so depleted of spells and healing. They rested up for the night and reattacked the Magekiller the next morning - and eventually did find Arrogan's treasure, although it took them searching throughout the entire Magekiller dungeon, after which time they had to backtrack to find out what they had overlooked, before they found it. But the tales of Arrogan all agreed he had been so full of himself he'd insisted he had never made a mistake in his life, and that proved to be the secret to finding his treasure, as "never made a mistake" equates to "always right" - by simply always choosing the right-hand path through the Magekiller, it eventually led to the wizard's hidden treasure (after discovering a series of levers, the one on the far right opening the way to the secret lower level which nobody had ever discovered before the PCs).
Johnathan
Once inside the cylinder, they noticed several things. First of all, there were seven metal bars sticking out from the interior sides of the cylinder, each about two feet long and pointing towards the center; had there not been a doorway cut into the cylinder, there would likely have been an eighth bar there as well. And finally, since they could see through the triangular holes at the bottom of the cylinder, they saw there was nothing but rock walls on all sides - except for directly across the cylinder from the doorway they had entered. So the solution seemed simple: everybody grabbed a bar and pushed the cylinder counterclockwise for half a circuit until the "doorway" in the cylinder lined up with the doorway to the south of the circular chamber.
This was accomplished, quite slowly and noisily (for the metal tips of the cylinder were dragging across the stone floor), but the wizard cast a grease beneath the metal tips of the cylinder and that helped. Still, it took a good half minute or more to get the cylinder repositioned so the PCs could travel down the southern corridor and see if they could find Arrogan's treasure. The corridor led to another circular room, this one containing an old, unworking fountain filled with what looked like brackish, algae-covered water. However, the "water" was actually an arcane ooze, which poured itself out of the fountain and attacked - not only with its acidic body, but also by "stealing" spells directly from the minds of the spellcasters, which not only lessened their spellcasting repertoire but healed the ooze. The PCs were forced to flee, back into the circular chamber with the metal cylinder, where they knew it'd take a good half minute to reposition the "doorway" back to the north (and that was with all six of them struggling at the task)...and in the meantime, the arcane ooze had no trouble at all sliding through the triangular openings along the bottom of the metal cylinder and into the chamber with those tasty morsels.... Eventually, the PCs had to forego any attempts at escape out of the dead end of their own making and concentrate on killing the arcane ooze before it killed them.
This trap didn't kill any of the PCs but it came pretty close, and after they had finally slain the arcane ooze they decided they were done messing about in the Magekiller for the day, opting to camp out where they were and not go wandering around any further to set off any other traps when they were so depleted of spells and healing. They rested up for the night and reattacked the Magekiller the next morning - and eventually did find Arrogan's treasure, although it took them searching throughout the entire Magekiller dungeon, after which time they had to backtrack to find out what they had overlooked, before they found it. But the tales of Arrogan all agreed he had been so full of himself he'd insisted he had never made a mistake in his life, and that proved to be the secret to finding his treasure, as "never made a mistake" equates to "always right" - by simply always choosing the right-hand path through the Magekiller, it eventually led to the wizard's hidden treasure (after discovering a series of levers, the one on the far right opening the way to the secret lower level which nobody had ever discovered before the PCs).
Johnathan
