D&D General Is this a fair trap?

[iserith]

I agree that the trap does work fine for 5e (except maybe for the yellow mold falling in fire part).

What I mean is that in a modern game, the "puzzle" of the trap also includes why and how it exists in a first place. Before, they'd be received as "ingenious". Now, they'd be plot holes. At least they would for me, in 2021

That's easy enough to imagine and explain. It is a game based on make-believe after all. Just need to make something up.

 

[Charlaquin]

Issues of the plausibility or practicality of the trap aside, it seems fair, in that it works in an understandable way, and can be detected and avoided or thwarted once detected. The one part that gives me pause is that dropping the block on the cube for some reason causes it to splatter on the characters instead of just killing the cube and making the treasure unreachable.

 

[iserith]

Yet one rope can hold all that weight...

It's rope made from the hair of the hill giants of the Frenzied Lands. It's extremely strong when pulled taut. It smells particularly bad when it is burned.

 

[Laurefindel]

That's easy enough to imagine and explain. It is a game based on make-believe after all. Just need to make something up.

Agreed! But that's what I mean; in a "modern" game, I'd expect the DM to have made something up already, or make something up that is coherent with what has been described in the game universe beforehand.

 

[AbdulAlhazred]

That's an overestimate so something is wrong with your calculations (a human and a block won't be significantly different here).

http://www.greenharbor.com/fffolder/speedtime.pdf

Either way, it's still screwed due to the pit constraining it. It will splatter vertically. You know this because you live in a world where physics applies. The ceiling would be covered in GC, but not the area around it. Maybe the 5' squares exactly next to it would get some. But if you have the lip you described it's going to be even more vertical than that.

On top of that you still have a slow deceleration into goo.

Goo which is probably ON FIRE.

Fire which kills Yellow Mold instantly (no damage, no hit, just fire kills it).

Even if it isn't on fire, the spore-explosion is constrained because the block is 10' down and surrounded by goo and possibly has goo on top of it even.

Literally the best-case scenario for this pit is someone jumps in without the slightest check, finds the invisible GC, and for some reason the PCs try to set it on fire with him in it (those bastards!), at which point the block falls, possibly killing him, and possibly exposing him to spores in the fraction of second before the Yellow Mold dies in a fire. I've explained upthread how to make a trap based on the same basic principles but which would actually work.

I really don't think the fire would be significant enough to kill the Yellow Mold. GC isn't flammable, so this 50 ton block of stone plunges into the pit, spraying GC everywhere (and there's enough volume in the pit to fill a 30x30 room 1' deep wall-to-wall, so there's going to be PLENTY of it going all over the place, though exactly what the shape and size of the splash will be is impossible to say without actually building the thing...

So, even a HUGE fire is going to go out, and the burning end of a rope IMHO is not significant enough flames to do anything to a yellow mold as it passes by, even at 10MPH (which is a fast run for most people). Just being pulled through a hole in a rock would probably put it out anyway.

I still say, with sufficiently careful engineering and craftsmanship the basic trap mechanism doesn't actually seem THAT far-fetched. It is clearly ridiculous in a Rube Goldberg sort of way, but we're already deep into ridiculous when we are exploring underground mazes full of monsters and treasure, so what?

 

[AbdulAlhazred]

I've never dropped a brick on a plate of jelly, but this thread is making me think I should, to do some concept-testing.

This also seems relevant to the issue of weapons vs this Cube. How do weapons hurt a Gelatinous Cube? Just by hacking it into little bits? In which case being in the pit gives it quite a bit of protection!

Well... don't start looking too closely at GC physiology, A WIZARD DID IT. Slicing into it causes it to lose hitpoints, which is fatal!

 

[Reynard]

Agreed! But that's what I mean; in a "modern" game, I'd expect the DM to have made something up already, or make something up that is coherent with what has been described in the game universe beforehand.

I don't think we have enough information to know whether this is "coherent with what has been described in the game universe beforehand."

What I see in this thread is fairly common: people have preferences for their own limit of "suspension of disbelief" and make the mistake of conflating that with some objective limit of plausibility. The thing is, they aren't related, your preferences and an objective good. At all.

 

[iserith]

I still say, with sufficiently careful engineering and craftsmanship the basic trap mechanism doesn't actually seem THAT far-fetched. It is clearly ridiculous in a Rube Goldberg sort of way, but we're already deep into ridiculous when we are exploring underground mazes full of monsters and treasure, so what?

And let's face it - Rube-Goldberg traps are a trope of D&D. Throw them in there from time to time and have a laugh.

 

[tomBitonti]

Making this more realistic:

Have the pit be topped off by a foot or so of brackish water. Let there be various skeletons of rats and things floating in the water -- and deeper. Remove the rope (the environment is hostile to it, so why have it?), and put a few recessed grooves in the wall to assist climbing into and out of the water. There are pressure plactes in the grooves. Remove the mold (why have it?). Leave a series of small boulders (say, 2' cubes) about thirty feet above the pit. The boulders are released by the pressure plate in the recessed grooves.

So ... the GC likes the pit. Often, rats and other vermin are attracted to the water. The GC swats them and eats them up. The GC isn't required to be invisible, as it should mostly blend in with the water.

The chamber is naturally damp, and quickly fills with water dripping from the ceiling and walls.

Removing the rope takes out a lot of the unrealism. The rope would quickly degrade, and why invite fire? That's just making things more complicated for no real gain.

Small boulders are easier to manage than a huge block. But big enough and high enough to make a splash. Putting them 30' up gives players a realistic chance to dive to the side if they are seen in time.

Of course, boulders falling on the GC ought to cause it a lot of harm. Maybe it regrows from scattered bits every time the trap is sprung.

I guess you could have a mold growing up on the boulders. It's damp, and there would be bits of GC flesh on the boulders from the last time the trap was sprung.

Problems: (1) A probable player interaction is to prod the brackish water with a pole or a pole-arm to tell how deep the water is. That will immediately reveal a problem, as the GC will resist the prodding.
(2) There is no bypass. A board put over the pit will be within reach of the GC.

TomB

 

[Dausuul]

See, this is where we get into the endless debates about GM-adjudicated things. You are correct, up to a point, IMHO. Beyond that... consider, a 10x10x10 block of stone weighs on the order of FIFTY TONS.

The block is 10 feet wide by 10 feet deep. Its height is not specified, but we can say with certainty it is much less than 10 feet, because the entire weight of the block is suspended by a single rope.