If you are from my group...

STAY OUT!

As, you can tell by my username, I enjoy using traps, so stockpile your traps here, regardless of challenge

A door that has a big spring mounted on it, that smashes the opener into a wall is one of my favourites

I'm a big fan of traps which don't mean life or death, but instead life or difficult. Falling into a new room with more challenges than if you hadn't triggered the trap. I'll post a few when I get the time!

Designed some sort of washing machine thing, it operates like a giant washing machine, but with super itchy brine (dealing 1d4 slashing for 1d8 turns caused by scratching). The players enter and try climb out then the brine starts, and 1d4 rounds later the foamy, slippy soap, so now we have itchy, slippy delivers in the center of the upside-down semi circle, so we now fire 2d8 crossbow bolts into the middle, for 1d12 rounds, so all in all, a very luck based trap

Apologies, this one is a bit hard and lengthy to explain, I used it as a 'sewer' entrace into a temple of Ghanadaur, here goes:

(Puts on best Rod Serling impression)....

Imagine, if you will, a boulder concealing a cave, once the boulder has been moved a cave opening roughly 5ft wide by 5ft high is revelaed. From the mouth of the cave you see the start of a tunnel, light peeks in but is soon swallowed up by the impenetrable darkness that lingers a mere 20ft infront of you. The smell of oil, pitch and a variety of other less tangible smells wafts out of the tunnel, do you dare enter?

The tunnel is actually 500ft long and for the most part retains the 5ft wide by 5ft high dimensions, it is naturally dark inside so torches can illuminate the surrounding but if darkvision is used then only subtle changes in black and grey can be seen.

Roughly 50ft from each end of the tunnel is a concealed trap door in the ceiling (DC15 to detect if using a torch but they are not detectable if using darkvision), this trap door is locked but no mechanism can be seen as the lock is on the other side.

Roughly 100ft in the walls and ceiling become slick to the touch, from here on the tunnel is treated as if coverd on the walls, floor and ceiling by an natural effect that mimics the Grease spell (DC15 for saves). This effect covers the tunnel from here on meaning it is difficult terrain and anyone walking the tunnel needs to make a Dex save or be knocked prone.

225ft in the tunnel loses its 5ft height and rise up in a dome becoming 25ft at its highest point before curving back down to a 5ft high tunnel some 50ft away, the tunnel retains the same slick coating as before and is still only 5ft wide.

The next 50ft of floor under this dome is actually a pivoting floor, stepping onto it causes the floor to swing down, dropping anyone that fails a Dex Save into a curved pit (the mirror of the ceiling above) and the floor locks in place becoming a wall with a loud click. When this happens the concealed trap doors at each end of the tunnel swing down blocking off the tunnel entrances/exits. A Gelatinous Cube drops silently into the tunnel from each of the rooms hidden by the trap doors and they start to ooze their way towards the centre chamber.

The floor in the dome chamber can be pushed from the verticle position back to a horizontal one and vice versa.

The party of PC's need to work together to get past the pivoting floor whilst the two Gelatinous Cubes creep up on them. Because of the size of the tunnel the Gelatinous Cubes fill the tunnels preventing escape. Should a Gelatinous Cube be slain and the PC's make it to the end of the tunnel the trap doors can be lifted back itno place to enable them to exit the tunnel.

That should be about it.

I’m always a big fan of the random booby trapped treasure chest, but it’s gotta be a cleaver one that just makes things more difficult rather than deadly. Like a treasure chest with a blowgun trap that shoots a tranquilizer dart that applies 1 level of exhaustion. It’s only a paltry DC 13 to notice the trap, but it’s a DC 17 to notice the second one. 😉 And with a DC 17 Dex save to avoid each of them. If you’re lucky the Player won’t check for traps at all and the PC will fail both Dex saves and *thok thok,* two levels of exhaustion. 🥱 

🤣 😂 🤣

Quote from Rob76 >>

Apologies, this one is a bit hard and lengthy to explain, I used it as a 'sewer' entrace into a temple of Ghanadaur, here goes:

(Puts on best Rod Serling impression)....

Imagine, if you will, a boulder concealing a cave, once the boulder has been moved a cave opening roughly 5ft wide by 5ft high is revelaed. From the mouth of the cave you see the start of a tunnel, light peeks in but is soon swallowed up by the impenetrable darkness that lingers a mere 20ft infront of you. The smell of oil, pitch and a variety of other less tangible smells wafts out of the tunnel, do you dare enter?

The tunnel is actually 500ft long and for the most part retains the 5ft wide by 5ft high dimensions, it is naturally dark inside so torches can illuminate the surrounding but if darkvision is used then only subtle changes in black and grey can be seen.

Roughly 50ft from each end of the tunnel is a concealed trap door in the ceiling (DC15 to detect if using a torch but they are not detectable if using darkvision), this trap door is locked but no mechanism can be seen as the lock is on the other side.

Roughly 100ft in the walls and ceiling become slick to the touch, from here on the tunnel is treated as if coverd on the walls, floor and ceiling by an natural effect that mimics the Grease spell (DC15 for saves). This effect covers the tunnel from here on meaning it is difficult terrain and anyone walking the tunnel needs to make a Dex save or be knocked prone.

225ft in the tunnel loses its 5ft height and rise up in a dome becoming 25ft at its highest point before curving back down to a 5ft high tunnel some 50ft away, the tunnel retains the same slick coating as before and is still only 5ft wide.

The next 50ft of floor under this dome is actually a pivoting floor, stepping onto it causes the floor to swing down, dropping anyone that fails a Dex Save into a curved pit (the mirror of the ceiling above) and the floor locks in place becoming a wall with a loud click. When this happens the concealed trap doors at each end of the tunnel swing down blocking off the tunnel entrances/exits. A Gelatinous Cube drops silently into the tunnel from each of the rooms hidden by the trap doors and they start to ooze their way towards the centre chamber.

The floor in the dome chamber can be pushed from the verticle position back to a horizontal one and vice versa.

The party of PC's need to work together to get past the pivoting floor whilst the two Gelatinous Cubes creep up on them. Because of the size of the tunnel the Gelatinous Cubes fill the tunnels preventing escape. Should a Gelatinous Cube be slain and the PC's make it to the end of the tunnel the trap doors can be lifted back itno place to enable them to exit the tunnel.

That should be about it.

 

 

 Dude, that is one of the best traps I have ever read

An anti grav floor in a room with no ceiling, so the sacrificial dummy, uhh, I mean lucky tester just flies off into space, never to been seen or heard from again.

I use it get rid of immortal or near immortal characters mostly, hopefully carrying some super expensive magic item and a lotta loot

One trap which I ade forever ago involved an underwater corridor which led through a treasury. If you pick up any gold from the treasury, as you swim over a yawning abyss on the way out, the gold becomes impossibly heavy and strength checks are needed to not sink with it. It even overpowers bags of holding, just to make sure!

It also gives them a chance to ditch it if they haven't picked up too much!

Perfect, using this against my money grubbing party

I like traps to mean something - beyond the "we don't want you to come in here". A lesson in not stealing, or thinking before one touches something.

You can always make underwater mimics, after all. Good luck fighting when you can't breathe!

A Tiny trapdoor in the ceiling (DC 20 to spot it) that opens to drop a vial of Oil of Slipperiness all over the floor near a spike pit if not disarmed. If it is disarmed they get to keep the vial as their reward.

A clearly visible yet intricate tripwire system at waist height. Doesn't appear to be hooked up to anything. If two people touch the tripwire at the same time, then they swap bodies a la freaky friday.

A golden cup with a grave legend about it. The first person to touch the cup has their sentience transferred to it, while their body turns gold. They can basically do nothing as they watch their party members decide whether to sell their body or look for a cure. (Better hope you have good friends.)

It really depends on the theme but I have some sort of common mundane ones that could be used by basically anything remotely humanoid:

• Trash mote: Disadvantage on stealth to cross quietly  often conceals other traps which will be poisoned or diseased  form the rubbish 
• Caltrops (bag of 20) potentially hidden in a trash mote
• Trap pit:  Hidden pit, often with spikes, maybe hidden in a trash mote. The pit doesn't need to be big enough to fall in it can just be deep enough to hide the spikes so people step in it. 
• Murder hole: Tunnel or narrow passage with  holes in the wall or roof for creatures to attack from. 
• False tunnel: often collapses for dex save  or bludgeoning damage and often trapping the target. 
• hunting trap 
• Crossbow trap:  Rope tied to trigger for crossbow, fires if door opened or trip wire triggered.
• Bell trap: sets off a bell on a trip wire or when a door is opened. Can just be a bell hung above a door so the door hits it when opened. 

Those are all very grounded realistic traps. Magic traps get really wild but i have some suggestions for hazards to mix into them 

• Radioactive: effects of sickening radiance .
• Wind tunnels: gust  or gust of wind push targets back.
• Gases: incendiary cloud, [/spell]cloud kill[Tooltip Not Found] or any monster ability (as per DMG you can often harvest these with a poisoners kit) so think dragon breaths 
• Angry ghosts or supernatural malice: spirit guardians 

basically any spell can work just make a caster with a list of spells that make sense and pick which ones you think are cool to be traps.

I mean I also like traps are very realistic, so why not add some chemistry to the mix?

Sodium+Water=A very very big explosion at over 200°c

Just fire bucket-loads of radiation at them like solar said, but you need to make it long-term and if you make a dungeon out of uranium, no one's ever leaving

A giant rolling ball, but it's also a magnet, so all massively armoured barbarians and whatnot are stuck on it

I love the idea of something which messes with metal (not least because it makes the Druid feature of no metal shine a little).

Just a room where the floor is an immensely powerful magnet - all non-magical metallic weapons and armour are pulled downwards, making it difficult terrain (1/2 movement), disadvantage on attacks, reduced range for metallic ammo and cannot jump.

Bonus points if this then turns out to be a puzzle, where the door is on the ceiling and you actually need metal in your shoes to climb up!

Knowing my party they would make a cart with metal wheels and pull the druid up in it

This may require suspension of disbelief but should be withing the reach of medieval engineers

Huge copper circle, hooked up to a gear system then a extremely fast running waterwheel, with a small copper brush rubbing against it, connected with a wire to an iron floor, and some batteries, these are the back up incase the wheel is stuck

That will create a humongous current and toast delvers with a low to medium con, and throw those with a absurdly high con for a loop if not toasted too

Everything is strangely clear as if the characters are looking through a film.

Then use a classic! GELATINOUS CUBE EM'!

Or one I'm using, have part of a well become a gelatinous ooze.

Or use mimics, gargoyles animated creatures, prisoners as Medusas. But nothing beats the good old ooze (theirs several different types).