Warning: Silly traps may easily annoy players. Of course there can be humour with broken or empty traps, or traps built by stupid people, but siliness at mass is hard to present properly.
But if you wish for such items, and the situation calls for it, delve here.
Here belong all the dart-shooting traps, where poisonous darts were exchanged for rotten apples or tomatoes, or simple eggs. And here is the electric door bell to be found (“OK. I ring.” - “Bzzzzt.” - “Ouch!”), and any number of grease that causes people to slip. Also, the undefeatable door that eats the only key that seems to fit (the one found on the other side of the dungeon), and opens on its own in the moment they give it up.
Use them, don’t overuse them.
(And as usually, feel free to add your own.)
Additional Ideas (10)
Solution: slide the weapons along the wall until it looses its attracting power.
The joke is, they bash with it the person that stands closest on their head. And withdraw. And they are pretty fast, curse them. If they keep trying, you could surprisingly open it on other sides, etc.
(Side note: the trap could be used against some strong enemy if they lure it back, and pay for the biggest club.)
Following them, the clothes come to a pit and jump over it (the jump is only an illusion), and anyone following it will hit right into the invisible wall. Ouch. In the pit below await the clothes, and possibly many others.
Of course, if you wanted to make it dangerous, it could be a death sentence to be in the near by city (city state) with such coloration. Used in royal tombs.
You pass a mirror. Out of the corner of your eye, you see it move seperate from yourself. You get a couple of scoobydoo moments, but eventually you see the mirror image move in non reflective ways. They will taunt you. They will make fun of you. They will do things to embarass you. They will keep you distracted so something can come and get you... or you waste a lot of time.
A pit lies concealed in the floor, artfully covered with a tasteful decorative rug. The players might even notice the delicate weave of thread through the rug, noting the almost sublime interplay of color and shape. As the rugs gives way, the PCs are dumped into a 20 foot deep pit filled with spongy balls.
These balls are a variety of bright and happy colors; Red, yellow, blue and green. The PCs have the usual task of getting out of the pit, but have to do so with the hinderance of being surrounded neck deep with these little balls.
The party are underground or in a tight fitting location. Theytravel up a slight incline and trigger the trap by pressure plate, trip wire, opening a side door with no room or hallway beyond, just a wall. A large, seemingly few ton boulder comes rolling down from a concealed section in the wall ahead of you.
The only option is to run the way you came but either due to the passage being smaller at the bottom (a possible door), or a pit trap slowing the crossing process, or a wall falling to block the path. The boulder rolls at a faster rate, with an odd lack of physical sound. No rumbling.
The players are pinned and the boulder comes crashing into them to smash open to reveal a cleaverly made paper boulder.
Many things can be within. I used this on my group and had clay jars of a sweet sticky liquid within that shattered and covered people with enough of it to be an inconvience only to later be assaulted by a hive of bees.
You could literaly tar and feather them in a similar manner. Clay pots of honey, tar, oil and then have a pit trap fall into a collection of feathers or something.
This seems like a fire alarm, with a button with "FIRE" written in large red letters below.If pressed a jet of fire shoots out and scorches the hand of the one who presses the button.