Trap 1: Wall Finger Trap (by Kurtis Swekla)
This simple and cliched trap may exist in any location with stone walls. Along one of the walls there is a small hole about the size of a finger or thumb. When the characters see this hole, they will see a faint red light emanating from it. With any luck this light will entice one of the characters to approach the hole and insert one of their fingers.
When a character does insert a finger (the hole is the length of one and a half inches) into the hole, they feel a heat on that finger, heat similar to sticking your finger into a pot of boiling water, and the character takes 1d4 points of damage. Immediately when this heat occurs, the character's finger becomes lodged in the hole. I am afraid to say that there is no way (magical or not) to remove the finger after it has been inserted into the hole. The only way to free the character is to chop the character's finger off.
The heat will persist for as long as the character's finger remains in the hole, causing 1d4 points of damage for every round that the finger remains in the hole.

Trap 2: Slide Stairs (by Kurtis Swekla)
This is a stereotypical trap for stairs. You can use this in any building or dungeon but for some reason I prefer to use it in the basement of a large house (i.e. a mansion). Make sure the characters are at the bottom of the stairs either fighting an enemy or running away from an enemy. When the first character reaches the top stair (not the floor at the top but the first step from the top) he triggers a trap which (you guessed it) causes the stairs to fold in such a manner so that all the characters on the stairs slide down them.
To have a little bit of fun with this simple trap you can add a hole that opens at the bottom of the stairs leading to an unknown dungeon, spikes, etc.. You could also add spikes on the walls so that the characters take more damage on their way down.
If the characters are going down the stairs instead, you can play with this trap so that when the last character reaches the first step from the top then the stairs fold into the slide.
This trap is funniest when the characters are running away from an enemy then they slide down the stairs to the bottom where the enemy is waiting for them.

Trap 3: Opening Floor (by Kurtis Swekla)
This trap's general design has been borrowed from the AD&D publication of The "Labyrinth of Madness." This is a very general idea for a trap, in which the characters are walking across a room and when one of them reaches the middle of the room, the floor folds inward. The floor folds along the middle of the room, downward into the ground, so that both sides of the floor (divided along the middle) fold in at the same time.
Give the characters a chance to escape by putting open doorways on both sides of the room (opposite each other). Below the floor you can put in spikes, a hidden room with monsters, treasure, or anything else that tickles your fancy.
If this trap doesn't hurt the characters, the least it will do is make the players very paranoid about the floor (trust me it happened to my friends when I used this).

Trap 4: Magic Mouth Pit(by Donald Hahn)

When the PC's approach this door a Magic Mouth says, "You don't want to do this...You really, really don't want to do this." If the thief fails his/her lock pick role a pit trap with stakes opens under them, 30 foot down. If/when the other party members pull the unlucky soul out of the hole the Magic Mouth says, "I told you so," and laughs evilly

Trap 5: Illusory Pit(by Chuck Cochems)
The party sees a pit. Observant characters will notice something odd about the pit. There is, in fact, an illusion of a pit, but it is a very poorly done illusion. It sort of shimmers when gazed upon for any length of time. The illusory pit is only 20 feet deep, not enough to kill a character. However, one inch around the illusory pit is the edge of the REAL pit the illusory pit covers. This real pit is MUCH deeper, about 100 feet and has poisonous spikes at the bottom, but they are not sharp and will only impale a falling character. People attempting to walk across the illusory pit will fall down in the real one, giving everyone else a save to disbelieve at +4 bonus to see through the illusion and see the real pit.
Solution: Don't try and walk over it. Either climb down, or levitate/fly over, or disbelieve and see the real one. Only people who say, "Bah, it's an illusion, I'll walk over it" suffer. Afterthought: There is treasure at the bottom of the pit.

Trap 6: Unopenable Door(by Chuck Cochems)
This one is a non-deadly trap designed to divest the party of its treasure. There is a stone door, which no magic or physical force will move. Beside it is a plate on a pedestal, with a statue holding a hand over it as if to suggest an offering is requested. However, any item placed on the plate simply vanishes! The party will put stuff that's not valuable in at first, and then work their way up, all to no avail.
The plate is actually illusory, and the pedestal has a hole. To open the door, everything must actually be REMOVED from the hole! There are gold, gems, some minor magical items (all left by previous adventurers) and one major magical item, left by the trap owner, to seed the trap.
Clue: Any item too big to fit in the hole does not vanish, but appears to stay on the plate (the illusion keeps you from noticing that it's actually on the pedestal and not the plate).
Solution: If a pole is placed on the plate vertically and released, it will reach the bottom and stick out the top, proving the plate illusory, and no save is needed to disbelieve the illusion. The illusion can also be dispelled, and the trap is otherwise mechanical, so this is safe to do (but no one will try it, because they will fear divine retribution)!

Trap 7: Illusion Over a Lava Flow(by Chuck Cochems)
A permanent Mirage Arcana has been cast over a lava flow to make it seem as a stream. In fact, as per the spell description, anyone who believes the illusion can walk right through, as it's cool thermal component will negate the heat damage of the lava! The trap comes when someone decides to disbelieve, due to being observant and noticing something odd about the illusion, and suddenly finding themselves standing in lava, which until then was not harming them. If they cannot leap for the edge immediately, they are toast, and everyone else must save, suffering the same fate if they disbelieve (they have a +4 bonus to do so!) If the illusion is dispelled, everyone is toast (no save) and the dispel will automatically succeed.
This will, though, melt and burn off all footwear, so when the party leaves their feet will be bare, but they will be otherwise unharmed, and will not notice that their footwear is gone until they leave the lava because the illusion hides the effect. Magical footwear gets a save, though rolled in secret (the generous DM will assume they save, as that's not the point of the trap).
Solution: Don't attempt to dispel or disbelieve the illusion. If either happens, you must fly or teleport across.
Afterthought: Now that the party has bare feet, the next room is full of shards of broken glass from broken POISON potions.

Trap 8: Illusory Bridge(by Chuck Cochems)
The party comes to a broken bridge with a 15 foot gap right in the middle. Attached securely to the railing is a wand, with a command word scribed on it (there is another wand hidden underneath the railing that the characters need to search around to find, and the description of this wand is below in the "Solution" part). If a player grasps the wand and speaks the command word, a shimmering bridge section will appear. Any character that steps onto it disappears. When the last character steps onto it, read the following passage.

"As you step on the glowing bridge section and lift your back foot up, your front foot falls through, and you lose your balance, and fall. As you plummet towards the bottom of the ravine, you realize that the wand must have had charges of the fabled Mirage Arcana spell, and your party members that had seemed to vanish had actually fallen through as well, and the power of the illusion had silenced the screams."

For that is exactly what happened. The wand has charges of a Mirage Arcana spell stored in it. Because this illusion has tactile components, NO amount of simple probing will reveal the spell as illusion! It looks like a glowing magic section of the bridge, feels like a bridge section, and any item placed onto the glowing bridge section will simply vanish as soon as it's released, it's fall hidden by the illusions effect. All senses are taken care of, and it's perfectly believable that the glowing bridge section could be a teleport zone. Only illusionists get a save to disbelieve until a party member (who is an illusionist) has successfully disbelieved, or someone forcefully strikes the bridge section, at which point whatever is striking will pass through, because the person's own mind will be unable to check the swing.
Solution: Cross the gap through other magical or non-magical means. Or use the solution of the designer, and grab the hidden wand, which is visible if you kneel and look up under the railing, and speak the word of command, and create a REAL magical bridge section which lasts until it is crossed by one creature. There is actually a permanent contingency spell which will cause the wands to be recharged.

Trap 9: Crossword Trap (by Bart de Waal) http://www.geocities.com/bartholemewnl (dutch)
This one can also be used as a puzzle. Get some weird font like Tengwar Quenya and make a table with letters. Look up a series of letters (like in a crossword puzzle) and write it under the table. Let the PC's walk in to a corridor with this puzzle on the wall. When they walk in, they're closed in because of thick wooden boards falling before and behind them. They are enchanted so you can't open them. Water starts flowing in. Now the PCs have to press each letter that you wrote down on the piece of paper (Like there doing a 1 word crossword puzzle). If they do it on time the doors will open. if they dont...
Easy to variate on and the strange font makes it fun (or just difficult). mailto:bart.de.waal@soneramail.nl

Trap 10: Thief's Finger Clone (by Jay Jones)
There is a treasure chest that is locked and trapped. The trap can only be disarmed with successful disable device and open locks rolls. In the case that either one of these rolls fail, there is a tiny razor blade that pops out and cuts the tip of the thief's index finger off. As soon as it hits the floor, the fingertip disappears, and is magically transported to a High Mage's Tower. Once there, the mage creates a clone of the Thief, which will seek out and attempt to kill the thief.

Normally about 2-3 days later, the clone finds the thief. The other party members are completely confused to which is the real thief and which is the clone. To make this confusion more realistic, the DM should have an exact duplicate of the player's character sheet, and secretly roll a percentage to see whether the player is actually playing his character, or if he is playing the clone...making sure the other players know this possibility as well. As in reality, the other players would have a 50-50 chance in attacking the party member vs. the clone if they decide to attack one of them. Disbelieving an illusion or any other type of magic, such as a Know Alignment spell, will do nothing, for the clone really is the character, just a separate part of him. This will hopefully convince the other players to let the thief and clone fight it out to the death, believing in the abilities of their friend.

Solution:
Having successful rolls on disable device, and then open locks will completely disarm the trap, until the lid is closed, in which case the trap rearms itself.

Afterthought:
If the clone fights the thief and wins, he will stay with the party, as the original thief. Let the player then play the clone, and secretly try to kill off each player. Let the player know in secret that his new mission is to kill off each character, without getting caught. A perfect way to have a rebel NPC in the group, without the players knowing and using player knowledge to kill him.

Trap 11: Unnamed (by Paul)
Long hallway filled with mirrors. One of the mirrors is a mirror of lifetrapping and another is a mirror of opposition. Others could be gateways.

Trap 12: Push Me (by Armand)
The PC's are crawling through a small little tunnel when the PC in front reaches a dead end, in front of him is a button and beside it is a plaque which says "Push Me." If the button is pushed make something nasty happen such as acid spilling from the roof. The trick to this is to push the plaque (the plaque says "push me" not the button) and the wall will open up to a room.

Trap 13: The Judge (by Blight)
This one takes a little setting up to do. The players will walk down a long hallway that has statues on each side, sort of like terra-cotta stone golems. The hallway isn't very well lit (yet).
The party comes across a statue at the end of a long hallway that has no arms, but sockets in the shoulders, and there are stone arms lying on the ground nearby. Now, assuming the party is looking for the end of the dungeon, the boss, whatever, they'll try to figure this out. The arms on the ground can be put into the shoulder sockets. The problem is, you can't really tell which one is the left arm and which one is the right, since the arms are perfectly straight and the hands of the statue are crude, flat, stone paddles.
The characters can slide the arms up and down a bit. Sliding one up brings the other down, etc. If they move the arms too far it sets the trap off. Moving one too far down to the right makes the room flash with bright light, blinding the characters, and activating the stone golems. Moving one too far up to the left, and the room floods with darkness and activates the golems. If the characters fix the arms JUST right in the middle (DM's discretion on difficulty), the room will flood with a grey light and they will hear a loud click and one of the statues will stand away from his alcove, revealing a passage.

Trap 14: The Charlie and the Chocolate Factory Death Machine (by ed)
The PC's walk into a room roughly 20' by 20' by 80' tall. In the centre of the room is a table with a Potion of Uncontrolled Levitation (see magical items) The ceiling of the room hides a trap of some sort behind an illusion (spikes, spinning blades, turning gears, etc.). Get the picture? Oh yeah, burping won't help this time!

Trap 15: Terminal Velocity Dimension Doors (by Gary) In a dungeon or hallway with a height of 10 feet. The floor has a Dimension Door on it and one on the ceiling. When anyone steps on the floor he is transported to the ceiling and falls to the dimension door on the floor then transported back to the top just to fall again over and over. How long does it take to reach terminal velocity? Someone better throw a rope over the way real fast. The trap can be dispelled but it better be done fast or else the unlucky soul will bounce and hit the ceiling a couple times, or die from the impact on the floor.

Trap 16: The Moving Tomb (by Wargreymon44)
This is more of a trick than a trap. It takes an experienced DM to pull it off without confusing himself. It can be used for any map.
Put switches in the tomb with the players. I would say for a small tomb put at least 5 switches spread out in the tomb. Now every time a character pulls a switch a wall moves or a door that was once unlocked; locks (or is covered by a wall that slides over it thus giving the appearance the door has disappeared). I like this trap because it is a good laugh on slow days and it keeps players on there toes. This is also a good brake from normal hack 'n' slash combat that I think everyone gets sick of after a while. I did this in a rather small temple and they spent the best part of 2 hours trying to get out.

Trap 17: The Cube (by dialtone)
I got the idea for this dungeon from the movie "The Cube." It takes quite a bit of setting up so you have to be in the mood to do it. First get a piece of foam cork board and cover it with 1.5 inch grid paper. Now cut out and number 99, 1 inch cardboard squares (card stock works well). Next write up a description of 99 rooms. Some are trapped, some have monsters, some have treasure, some have nothing. Now drop your PC's off in random rooms in the Cube (figure out a hook, you're the DM). Now as the PC's make their way from room to room, the cube moves and changes. Example: Players 1 through 4 either search the room, fight orcs, or defeat a trap, and move to the next room. Now the rooms reshuffle.
The method I use is a three step process. 1. every other row shifts to the right 2.every other column shifts up. 3. the blocks on the outside move around to take up the empty spaces. I suggest you make the board first then figure out the pattern to use (it can be confusing listening to me ramble). The trick is for the PC's to make it to the room 1 position in the Cube, that is where the exit is. But first they have to find each other .
Tip: Make some of the rooms look the same. i.e. one room has lion statues that shoot magic missiles and the other has lion statues that pour gold from their mouths. Makes it more sadistic.

Trap 18: Got Ya (by naomi)
Have an evil monster be in a room and when someone walks in, the door slams shut behind them. After that they must search the room and in the center of the floor they see a switch. If they go over and step on it then an elevator-like pedestal falls on them and kills them but if there is more than one person only one person is killed then a big, hard to beat monster will step off the pedestal and will fight the others

Trap 19: Tasty Treat (by Anon)
A pit full of whipped cream. Can't swim in it, can't breathe it, even with spells (no breathe cream spell exists), too thick to throw a rope into it, unless weighted, and even if one is thrown in, finding it is impossible. Sound doesn't travel well in whipped cream either, so the pathetic bugger in the pit is inaudible, and can't hear anything excepting explosions and other loud sounds.