Do you think this will kill my players? Or will it be too easy a puzzle?

I wanted to provide an interesting puzzle to fill the not so interesting Mine Tunnels at the Entrance to Wave Echo Cave. I did some searching and decided it should be timed sorta like an Indiana Jones encounter, it should have both environment dangers and monster dangers, and it should tell a personal story that further explains what happened to Wave Echo Cave.

I'm about to run it soon. Please give some feedback.

Here's what I came up... PDF Google Drive file:

https://drive.google.com/file/d/1u0zVD-htBCf_mdcwIVDaGsKLRv67b5_t/view?usp=drivesdk

This area of the dungeon contains a timed puzzle, one that explores the story of a wizard who was trapped by a cave-in that occurred during the orc invasion.

Elenthil the Delver was one of the original wizards who used his knowledge of elemental magic to excavate and harness the cave’s magical connection to The Weave. He was trapped by the cave-in and went mad in his solitude while the power of the cave’s energies surged through him. He tried to use necromantic magic to revive his beloved, long dead Lily. His attempts are the cause for the undead dwarves, humans, and orcs that roam Wave Echo Cave.

In the wizard's delusional final years, he used the magical energies of Wave Echo Cave to make several of the tunnels into warped illusions of his memories. Using the dial mechanism the dwarves built into the mining complex, Elenthil could live and re-live them over and over. In fits of delusional rage he unintentionally summoned deadly monsters matching the moods of his damaged mind and trapped them in the tunnels behind the time mechanism.

Once the mechanism is engaged, a timer starts that affects the abandoned mining tunnels according to the elements of the season designated on the sundial mechanism. After two minutes, the dial mechanism disengages and can be advanced only by a dwarf; if it is not engaged again, the tunnels soon become overrun by the elements and the party will most likely die. The only way to get out of the tunnels without dying or causing another devastating cave-in is to retrieve the treasures from the monsters, summoned by Elenthil’s damaged mind, and give them to the illusion of Lily by the shore in tunnel 11. This action opens the passages to Wave Echo Cave.

I'd be vary careful of this line "if it is not engaged again, the tunnels soon become overrun by the elements and the party will most likely die."  You are very close to mechanically giving your players an ultimatum. Always have a  way out in your back pocket if you find your players didn't quite get how things work or what's happening and you need to rescue them or delay the impending doom to better explain it. ie. the ecumenism fails or something.

DasAmigo,

Thanks for taking a look. I appreciate the feedback.

I know you're not supposed to "corral" your players too much because it leaves less room for spontaneity, but I was planning on making the environmental hazards (choking vines in Spring, monsoon/rising tides in Summer, smoke/lava in Fall, and snow drift/blizzard in Winter) literally corral them back to the mechanism, so that the only available space left becomes the area around it. If I have to fudge the rolls a little or grant inspiration prior to the encounter, I'll explain the near death experiences similar to what you described.

I'll consider some other ways to get through the encounter. It's often hard enough to design one encounter, much less multiple paths of success.

Any way that you can use smaller fonts/ wider margins so that it won't waste 20+ pages?

Encounters seem to be geared to around CR5 more or less... That's probably appropriate. The main problem I see with this trap overall is the expectation that your characters will 1) find all 5 treasures, and 2 think, even for a second, maybe I should give these awesome magical artifacts to the ghost/specter. Maybe the specter attacks if the characters appear to dawdle/hesitate?  Also, I think this trap has some NICE loot. Perhaps too nice. +8 1/day spells +4 resistances, at will clairvoyance for 2 characters.... but that's up to your discretion.

I've become a fan of writing puzzles with no set solutions. Anything the players come up with that sounds reasonable, we can go with that and see if it works.