My favorite trap. Hmm...
This is a trap designed to seriously hurt. The degree of the attack delivered by triggering it is left to each GM's discretion.
Imagine a path of crystal blocks. The blocks all vary in size, averaging 6"x12". A sign by the path, or on a door that opens to the path reads: Follow the path of gold to safely pass. The first time I used this, I had a room full of elven trees hanging heavy with golden leaves while the walls and floor were covered in hammered gold. The path winds across a 100' room, darkened. At the 100' point, it takes a sharp turn and goes another 60', ending (at a door or a gateway or whatever).
The blocks of crystal or opaque, but if examined closely (hard perception mnv) a rune can be made out in each block. One rune is AG, the other AU. Use whatever language or skill you wish for the PC's to figure out what those runes mean. Step on the wrong block, and the trees release a hail of thorns and grapple attacks, or the golden wall unleashes a blast of magical energy. I once even had spears erupt from the walls and floor, impaling everything in the room with 1d10+5 random puncture crits. Whatever. For low magic settings, exploding canisters can fall from the ceiling, ceiling blocks crushing, pits open, etc. Summoning monsters is another option for more combat oriented GM's.
The key is to throw small tonnage of worthless misinformation at the PC's. Their pointless experiments will miss the obvious and cause great harm. The type of attack can be modified to fit your style, such as each wrong step teleporting away random items on the PC, aging them or working good ole RMCIII Warlock changeling spells, slowly altering and twisting the hapless PC into something nasty (tentacle arms anyone? A four foot telescoping neck?). This trap is best played old school style imo. If a player examines the blocks, they symbols will be seen, the trap solved and easily bypassed. Well, how easily is again up to the GM, who may demand a mnv to walk the path without stepping on a wrong block (crunch movement rates to calculate how long it takes and difficulty of mnv based on light, size of blocks, etc).
It helps to make the room a magic dead zone, or have attacks triggered by attempts to cross room with magic/spells. This should be detectable with Sit Aware Spell Casting. Reality Awareness, Spell Lore and Warding/Symbol/Glyph skills could be useful in seeing the danger, again as fits a GM's respective style.
