Just thinking.. Evil ways to use that Gelatinous Cube!
Early morning thoughts...
In a dark cave, a āfloating ā sword, glowing wand or even a suit of armor might entice a reckless group of adventurersā¦ all along its a gelatinous cube
I always loved the gelatinous cube. Itās straight to the point. Its a trap monster that eats the greedy and keeps your dungeons sparkling clean too!
Letās think about this for a momentā¦
What does āfloatingā look like in the dark? Players with torches see glints, maybe shapes. If they carry lanterns, the light is steadier. I imagine a faint shimmer, like something just out of reach. Too clear, and they wise up. Too vague, and they ignore it. I would describe surfaces first. A shifting reflection. A gleam that moves when they move.
Second, timing. A cube only works if the party enters its space. It is slow. It needs the players to come to it. So the cave has to funnel them. A side passage, narrow and wet. Maybe something is chasing them deeper. Or something valuable lies behind the cube. Let them see the prize first.
I would not make it random loot. Give it a story hook. A knightās armor. A wand that hums with stored light. Something worth stupid risk. If a player pokes it with a pole, the cube reacts. You are not hiding the danger forever. But you want the decision to feel earned.
Random thought: Cubes were man-made to protect things and it goes out of control at times.
So how clear is this cube?
That is always one thought that crosses my mind. In a dungeon situation, with torches, I would think it would be clear enough that the party wouldnāt realize itās there and the front line would walk into it?
But normally cubes have things in them floating around, which would tip off the front line. WHAT I could do is put a suit of armor in the cube, against the wall. Which would make a party stop and investigate. Getting close up towards this armor, and start inspecting it. Which is when they get close enough I can hit them with the save. After that, the surprise is over, but it will be fun to try to nab one or two greedy players.
Ideas:
Keep the cube between the players and what they want.
Use narrow spaces to prevent easy avoidance.
Give the treasure a name or small story.
Roll for surprise on approach, not initial sight.
Let players talk themselves into danger.
Offer a dark out if they want to survive at a cost.
Cube as a third party in a fight. PCs and NPCs can shove each other into it, and it is mobile cover vs archers.
Cubes in a long connected series of halls, with many self-closing doors. They just wander the halls which makes a limit on how long someone can be in the hall before getting swept. Gotta room hop.
Cubes as parasite removal for a black dragon (immune to acid). Restricts movement and archery in the hoard room. Metal hoard immune to the cube.
Cube in a gatehouse between the inner and outer gate. Open either gate without letting it into the side passage first and it moves into you from a mere 5' away and out of sight behind the gate. Sucks to be the guy at the front of the battering ram. (Yes it was a dick move, but I still think this was funny).
Previous adventuring party trapped a cube in a closet and locked it.
By some weird statistical thing, my earliest dungeons always seemed to have a G/Q in the first or second room. It got to be a running joke, so that eventually I gave up on them entirely. Then I got creative: sliding the cube into the one known way out; having it slide around a pillar or stalagmite and appear less cubish; make it smaller but speedier; set it underwater in a water channel the party must move through. And all the gunk and gakk it accumulates along its journey makes it confusing to see.