Let’s face it: magic dissipates after a time, creatures die or fall apart, and even poisons loose their effect eventually. But a sturdy mechanism, be it just a simple affair or a complicated machine, can hold for centuries, millenia if you are lucky.
And then there are the pit traps, smartly constructed rooms and countless other ways how to make sure your privacy is undisturbed. Do not underestimate them: they can be much cheaper than the alternatives, and much more reliable.
Feel free to add to this scroll.
Additional Ideas (12)
The problem for the pc's in-game arose when they spotted the tripwire and disabled it. They gummed-up the holes where the wire ran through, and cut it. This meant that the floor would now not move, and cut off their way that they came in, as well as the way to the werewolves' den. Instead, they now had to make their way down to the bottom of the chasm & back up on the other side. The players didn't find out that the floor was even supposed to move until I revealed this after the adventure was over... They had heard the odd sound from the floor moving (the werewolves moving about), but didn't discover what caused it until I told them after the game.
It is in a long hallway or set of hallways. The floor is stone or tile. Underneith a few tiles are mechanisms that "click" when you step upon them.
So people are walking along, and they hear a somewhat audible "click". They then panic and dodge. This happens a couple of times as they go down the hall. After they walk along for a bit, they can see at the far end of the hall there is an open "pit" where the floor swung open. It does not move when the clicks occur. They assume that it is a broken trap. The last click just before they reach the edge of the pit causes the floor underneith them to half drop to an angle, sliding them into a set of angled spikes or a water trap.
(see a follow up to this trap below My Second Favorite Trap )
In a very large and very old city (Citadel, Formour), the inhabitants have built additional layers, so that what was once ground-level streets are now subterranean sections. The pc's are slogging through the darkness and making a wide turn through what was once a curved road. They had a recent encounter, so only one person was carrying a torch, with the rest armed and ready. As they rounded the bend, they saw a glimmer of torchlight ahead and heard accompanying noises. They quickly dropped the torch, ducked into an alcove (what was once the opening to a shop), and noticed that the other torchbearer did likewise. Peering carefully around the corner, they could barely make out in the dimness the gleaming of metal from the other group, armed and ready for battle. After arguing about what to do and failing to come to a mutually satisfying plan, one of the guild rushed out--seeing a member of the opposing team running to meet him--and fired his crossbow... Crash! Shattering glass rained down with a deafening noise. There was no opposing group. The pc's were afraid of their own reflection from an old large pane of glass left in an abandoned storefront. The torch and gleaming metal of weapons were their own, and the noise was just echoes. Their own paranoia was the trap.
This one has been done numerous times, but bears repeating. There is an obvious pit in a corridor. It can seem bottomless, be spiked, have a waiting monster, whatever--it's an ordinary open pit in a dungeon. The pit is a bit too large to safely jump, especially given the ceiling height, but there is a small ledge one one side. If they are careful, the pc's can scoot along this ledge to the other side--scary but doable. However, once the group is starting across (especially if they don't go one at a time), the ledge falls (simple weight-activated sliding bar) or crumbles, dropping them into the pit. Even if they only go across singly, you can still have one or more people on either side, with someone trapped and possibly dying down in the pit.
This is an idea I used many many moons ago, when I was rather a novice GM. It works best if the pc's are running from an encounter, or have other reason not to notice small sounds or an odd floor. Prior to this trap, the flooring consists of rubber mats over gravel, uneven sections, and the like. Once the players start to get bored of this as "flavour text dungeon dressing" you spring the trap. The hallway opens up so that the floor is all that they can see in their light radius, and it makes a wide corner so that they cannot see very far either in front or behind. In a fantasy setting, you can have an air shaft blow out their torches to further cast them into darkness. Inside this section of hallway is a large and well-oiled treadmill, tilted slightly upwards. The player-characters have already become accustomed to odd walking surfaces, and the air shaft or chasing monsters will hide whatever small noises the treadmill makes--as will the pc's own noises. The troupe can potentially walk for hours without gaining any ground, and the area is frequently checked by local dungeon dwellers who know of this trap & how to get the tasty treats it holds...
This trap must be later in the dungeon where my favorite trap has been sprung. If not sprung twice (once for spikes once for water). Down the hall, if you shine the light, there will be a pit. When you walk forward, there will be a click.
Okay same drill as before... so the characters get bored and since they know the score for this trap, they are pretty careless. This time, about halfway down the hallway, the click triggers extending spears. Either way you move down the hall, once the center click has been activated... the extending spears will shoot out of the left and right walls (at varying heights) as you move up or down the corridor. Eventually the spears retract, set to spring again.
A set of stairs leading to a mansion door would be a nice setting.
The trap is laid by having a section of floor cut out. A support beam, or several beams, holds this section of floor upright in its place from a burrowed out cave below, or even a set of tunnels. A small section of floor should be selected, perhaps 3' in diameter.
When the victim steps up on the cut out platform a ghoul pulls the beam out from the supported floor piece, thus causing the PC to fall to their doom. The fall itself may only be 6' or so and not even cause any damage. The 6 ghouls that wait below is another matter. Once again this one is not technically a trap, its just a support beam. Its not the floor's fault, someone pulled the beam.
This trap is used by paranoid keepers of ancient libraries, sorcerors jealous of their knowledge, and other book lovers everywhere.
A very simple trap, it involves distributing various volumes throughout the library, or in regions of very sensitive books which the trapper believes are important. These trap books appear to be a regular book in every way, but their pages usually contain nothing but gibberish, and they are poorly bound. Hidden amongst the pages of these books are flexible leaves of razor-sharp metal- when the libral trespasser innocently takes hold of the book, flipping through it's pages, said trespasser finds their fingers and hands quite hideously damaged.
Of course, this trap functions almost purely by chance- an innocent chooser may be just as likely to take hold of a true book as one of these trap books. But many have found them to be excellent, especially in the tracing by blood-trail, if not the killing, of book thieves.
Quote from CaptainPenguin: "This trap is used by paranoid keepers of ancient libraries, sorcerors jealous of their knowledge, and other book lovers everywhere."
This trap works for books that are hand scribed and of stiff paper. Many of these books have "scripting" in the upper or lower corners, perhaps inking along the very outer page edge. The ink of certain books include a deadly poison.
How this works: People who read often lick their fingers to get a good grip on the paper when they turn the page. The ink transfers to the finger. The finger transfers to the mouth. The reader slowly poisons himself as he turns the pages.
If you know it is a "dangerous book" you just take care not to lick your fingers - using something else to move the pages.
Thank you CP for dislodging this idea from my brain.