21. Maths Puzzle
The walls of a room are made of bricks with numbers engraved in them, from 1-999. The party has already found three strange artifacts, shaped like this:
Solution: Push brick 18 (2 x 9 = 18) for a bonus. All others are traps.
22. Capture Enemy Mage
The party enters a mage's sleeping quarters to find him asleep on a bunk. They can capture him and interrogate, but must beware of verbal-only spells and sudden escape attempts.
23. Glass Ceiling
Stuck for a way to get out of the dungeon, the party enters a room with a glass dome 50' up for a ceiling. Through the glass they can see the sky. Solution: Smash glass and climb or fly up.
Afterthought: Shards of falling glass do some damage if they didn't get out of the way in time.
24. Dead Rat
Inside a treasure chest the characters find: a dead rat. Inside the rat is a 1000GP gem - and if they don't cut it open they'll never know.
25. Killer Veggies
A good trap to use if the group isn't cooperating. The first character in line opens a door to be grabbed by some strange vegetation. The victim will be digested in 30 seconds, and the only way to free them is for EVERY member of the group to assist in pulling them out.
26. Scratches in Walls Near Lair
Observant characters will spot long scratches on the walls. They should thus be prepared for a surprise attack by a wererat, or equivalent. If nobody commented on the scratches or what they could signify, the monsters automatically get surprise.
27. Invisible Force Field
A valuable item sits in the centre of the floor. If anyone tries to get near, they'll feel bars pushing against their chest and legs. Note that tall characters will NOT feel bars against their head, but you don't have to tell them this unless they ask. The bars are only 5' high, but it will take some experimenting to figure this out. Once they know, magic or a good jump should get them over.
Afterthought: It could also be set up so that the bars are 8' tall, but only surround three sides of the item.
28. Greed Trap I
A 20'x10' room with a door at each end. The floor is covered with gold pieces. The party can take as many as they can carry.
The problem is, the gold is what's holding the floor down. The moment more than 150gp leaves the room (like when the first character leaves, and the others are still there), the floor will shoot up and slam them against the ceiling (or drop out from under them).
29. Greed Trap II
A gently sloping corridor 5' wide and 100' long. Darkened. Every 10 feet there is a valuable item of some sort. The slope gradually steepens and becomes slippery. After 60', the characters cannot get back up, and will slide into a deep pit at the end of the corridor.
Afterthought: Roping the characters together will fix this problem. They could also try descending into the pit and finding the treasure left behind when previous people fell for this.
30. Doppleganger
One of the adventurers (better make it an NPC, to be fair) is silently killed and their place taken by a doppleganger. The doppleganger has all the powers of the person it killed and will betray the group at a suitable moment.
31. Humungus Fungus
A 6'x6'x6' soft green lump in the centre of the room. Can climb over it - carefully - with no trouble. If it's punctured, spores do LOTS of damage.
Afterthought: Several other, smaller, green lumps are seen throughout the dungeon. They gradually grow and multiply.
32. Trapped Demon
A demon trapped in a magic pentagram tries to persuade the characters to release it (promises gold, etc.). Upon release, the demon attempts to kill the party.
Afterthought: If the character has knowledge of the creatures origin (perhaps a religion non-weapon proficiency), they may be able to guess the demon's intentions.
33. Tall Room and a Bucket
The characters are in a very tall, but thin room. There is a trap door on the ceiling and a bucket of water sits in the corner. The walls cannot be climbed and spells are ineffective in the room. If the characters empty the bucket (spill, knock over, etc.), they notice that it magically refills.
Solution: Keep emptying the bucket, fill the room and swim up.
34. Controlled Player
One of the characters picks up a sword (or whatever), and is immediately controlled. The rest of the party must use unarmed combat to remove the weapon, without killing the controlled character.
35. Rescue Prisoners
The party enters a jail of some sort. After killing the jailor, they rescue the prisoners. Some may be reliable, some could try to betray the characters.
Afterthought: One of them is a lycanthrope. Or a vampire. Or a polymorphed evil mage.
36. Good or Evil
The spies a band of orcs guarding three wounded people, but something doesn't feel right about the situation. A perceptive player will notice that all of the orcs are carrying ornate broadsword (uncommon for orcs), and the wounded humans are licking their wounds and snarling. The magic in the room is actually playing tricks on the players, and creating an illusion - The orcs are actually soldiers guarding three wounded orcs.
37. Pictured Door
An enormous room is lined with large, heavy tapestries. One of the dozens of tapestries show a corridor, similar to the entrance. Surprise, the tapastries is actually a magical door.
38. Dud Money
A large bird is seen lying in the corner of a cave. Not far from the bird is a chest full of coins. Surprise, the coins are actually tiny eggs, with an illusion cast upon them. Attempting to pick up the "coins" will shatter an egg and alert the large bird to the parties presense.
39. Catch 22 Pit Trap
A player character falls in a pit, taking standard falling damage and separating him from his comrades. In the pit are two levers. The first lever throws the player out of the traps with 3d6 dmg from the force of landing or hitting the ceiling. The other lever will let off a full fireball above the trapped player, getting his comrades.
40. Teleporting Pit Trap
When the player falls in he is teleported to a random location. If his companions follow, they might go to a different location.
Afterthought: Good for separating parties. The same trap can be used in a doorway - A player walks through a doorway, unaware of the portal, and is teleported elsewhere. His comrades may attempt walking through (thinking they will end up in the same place as their friend), and end up in a different place.