D&D 5E Designing a Deathtrap Dungeon

[RangerWickett]

But it needs to be sporting.

So imagine there's a planar conjunction every X hundred years and it just so happens to occur on the night I need to run a one-shot for my gaming friends who are in town for the holidays. Said conjunction throws those friends into a fantasy world, but also makes them semi-immortal. If they die, they respawn at whatever bonfire/save point they last rested at, returning to life 5 minutes later.

The players have until dawn (both in game and in the real world) to get to the bottom of a deathtrap dungeon. I'd like some help in designing it.


Some Ideas
Mechanically, I'm thinking of doing D&D Next, and the party starts at 1st level. Every so often they'll gain a feat, or a +1 bonus to something. But I need it to be simple.

I'd like there to be traps, and monsters who require some clever thinking to defeat. Ideally most of these things should take a few attempts to get through. Try once, die confused. Try a second time, die but figure out the trick. Try a third time and pull it off.

I've got 3 days to come up with ideas.

 

[Greensnakedrex]

That sounds like fun! How about a mysterious room that appears to be untrapped but actually infects the PCs with a horrific disease which kills the characters several rooms later. Perhaps you could use a binary poison- the air in one room is the first agent, the water you wade through in another room is the second agent. You can avoid the trap by holding your breath, or if the trap is disease based, you could purify the room with fire.

I think it could be fun to have a room where the characters meet the reanimated corpses of themselves from their previous deaths. Would be cool to stumble upon the horrifically burned 'dead me', the decapitated 'dead me', the flayed 'dead me', and so on.

How about a mind compulsion suicide room- see a mysterious rune, enter a dazed delirium, jump into spiked pit. The rune could be a recurring theme throughout the dungeon. The characters stumble upon one, the die, but they know where it is now. Then they have to navigate the room with their eyes closed. Could be cool in conjunction with other traps/obstacles.

What about a room where the pc's have to pile up their own dead bodies to solve the trap- as in a counter weight for a mechanism or a raft across piranha infested waters or an acid pond.

 

[RangerWickett]

"Solve this puzzle with a pile of your own corpses." Fantastic!

 

[Quickleaf]

[MENTION=63]RangerWickett[/MENTION]
My Dragon Mountain conversion is teeming with traps, some of which are just mean and others which are quite ingenious. Toward the end in "Approach to the Lair" are some classic D&D death traps like reverse gravity pit traps, poison flammable gas in dark rooms, etc.

http://www.enworld.org/forum/showthread.php?331204-Dragon-Mountain-(4e-conversion-complete!)

 

[GX.Sigma]

A library where all the books fly off the shelves and attack anyone who makes noise.
A fight on a seesaw over some lethal hazard.