I'm finishing up my ruined elemental academy for tomorrow, and one room that is giving me some trouble is the room that is the earth font. Each of the elements has a room that is tied to the plane of the appropriate type (water, air, fire, earth). Originally each of these rooms was a test to ensure that talented students would only be able to progress to the three rooms beyond. Fire requires resisting the fire, water is a tough swim, air involves flight or crazy jumps.
For earth though, I'm just not sure what I should do for the room. It has to be a test that simply crossing the room involves. I have contemplated collapsing the room and forcing the party to come up with a way through an obstacle of that nature.
Some of these obstacles I'm not convinced they will do tomorrow, but they can return later on after finding a way through to attempt it then.
Any thoughts on another challenge that I can do for the earth room? Do you find groups when presented with challenges like this that they cannot solve ever remember to return for them later on? It is something I saw back in 1E and some 2E, but seems to have dropped off in what I have seen as the years have rolled by.
I would suggest making it climb base. Make the room have a steep grade and be mud, loose sand, shale, or something similar. You could also make it a cliff face if you want more risk of injury for failure. Perhaps put in extra "traps" that make large section break free and require a jump to grab onto more solid ground.
Of course if they can fly this is an easy room, so you may have to come up with alternatives for that.
How about this:
The room appears to be solid stone. But after getting in 10 feet (through the solid stone), the PCs find that the interior is filled with rocks of various sizes, from small pebbles to large boulders. The interior is also a hundred feet tall or more, so if they clear out some rocks, more fall down.
Inside the room you can have some sort of earth elemental creature that eats pick-axes and any other tools the PCs might try to bring in.
I like the climb idea. It brings it away from some high powered spells and makes it more doable. Plus, it means that people who have those spells can just power through by punching through the area with Passwall or some such. Intense gravity can get around the problem of the fly, and also make it interesting as you begin to sink into the soft earth if you stay in one place for too long.
I think that is what I should go with then. It combines my idea of the filled room (or the solutions to that problem) with other solutions.
