What makes a room in a dungeon replayable? I want to construct a dungeon maze using four "rooms," each with teleportation rings that take you to one of the other four rooms depending on what key you use to activate it. What keys are available depend on where you're coming from. This makes a sort of maze of four rooms. If you're curious where I got the idea PM me and I'll link you to it. I'd link you here, but my players might see the map (A couple of them are scurrilous gits. You know who you are!).
So, depending on how well they remember a story I told them a session ago, they might end up going through each room several times. I want the rooms to remain interesting for three or four fights. The opponents will change (within a theme), and the room can change a bit and can be quite high magic since this whole complex exists in an extradimensional space and was created in an earlier age with higher than standard magic.
So far I'm thinking, loosely, that there should be some element of the terrain that players and monsters can manipulate (bridges, platforms, or something dangerous like a sphere of negative energy or something?) and some hazards to throw enemies into. There should probably be several areas without line of sight to the rest of the room.
What else? Has anyone done something like this where they made the players go through the same area and fight there more than once?
I have done this and it is very successful. The players love it because its familiar, nostalgic...and they love seeing new players discover some of its secrets for the first time.
It is a nexus of sorts that takes the external form of a large tower, which I call The Keep. It is an extradimensional space created by the Archmage Frigil Nubar. Within it he built the only successful generator of magical energy...too successful. The generator punched a permanent hole in the multiverse, merging many planes of existence together within its confines.
The Ice Spider, one of the ancient gods of the Wilderlands broke the thread that moored the The Keep in place, the anchor that held it to the location of its construction on the prime material plane. She did this to prevent the build up of magic from altering her Web of Souls and changing the destiny of the Wilderlands.
Now The Keep wanders the planes, randomly materializing in a new location every few minutes. Oftentimes creatures and beings who witness this are drawn in to explore the impressive edifice. Thus the entry chambers of the Keep can be populated with all types of potential encounters for the players.
Deeper within The Keep players will find doorways which open upon various planes of existence. These portals are permanent and are warded by some of the only permanent residents of the tower, the Great Dragons.
Meeting the Great Dragons and learning about them and from them is and endless source of campain material. Even after over 2 decades of people playing in my world and befriending them there is still plenty of mystery. The players have discovered that the Great Dragons live off of the magic that The Keep generates, keeping their great beings sustained. Though they do appreciate the occasional herd of sheep that the players manage to round up and through various contrivances bring into The Keep.
One of the Dragons has become somewhat of a patron to the players and has driven them to many adventures.
Some of the players have also encountered the Archmage and actually explored the area of the generator, a great chamber with its very own laws of physics.
The Keep is a place of adventure and a portal to anywhere in the multiverse, peopled with encounters and npcs who drive my adventures.
My initial design for The Keep is loosely based on "The Vanishing Tower" a creation of Michael Moorcock, who gave us Elric.
Well, you can't force something to be interesting.
You can atleast put stuff in you'd find interesting a few times over. But that doesn't automatically mean anyone else will.
Oh, come on, Noon, I could dose my players heavily with LSD and Ritalin and they'd be interested alright. Or dead, maybe. I'm not a pharmacist.
Actually I was more looking for stories like Tom's or suggestions about terrain and such. Maybe I'm being too vague. I'll try to whip up a sample room and post it this evening after work.
Tom, your The Keep sounds cool, but it's a touchstone for a whole campaign. I expect the players to be stuck in these four "rooms" for about two gaming sessions. They're not really rooms, of course, they're extradimensional spaces and can include pretty large areas with multiple rooms or even apparently outdoor areas if I like.
What kind of features make a room interesting more than once? Most traps would be dull after you figured them out, but the right one might be good. Maybe one you can disable with varying levels of success?
Maybe I'm looking for a fire swamp set up. I mean, what are the three terrors of the Fire Swamp? One, the flame spurt - no problem. There's a popping sound preceding each; we can avoid that. Two, the lightning sand, which you were clever enough to discover what that looks like, so in the future we can avoid that too. And the ROUSes? I don't think they exist.
I see...What you are bringing to my mind is a large complicated clockwork that is spread through your four rooms. The clockwork moves and shifts the rooms around relative to one another. The goal is to get the rooms in the right sequence that opens up the exit or doorway leading to the other side. Wrong combinations initiate traps or reset the clockwork or open the wrong doorway.
I can imagine the first time through that the players are chasing a madman through who knows the mechinations and is staying one room ahead of the players and activating traps and devices to slow them down...This gives the players a taste of what the contraption will do and something of how to control it to achieve the affect they wish.
With enough combinations and various results who knows what the players will unlock...but hopefully they will be interested to go back through and use the device in their favor only this time they would be keeping one step ahead of a creature they lured in etc.
hmm I may have to start building something like this myself, sounds like a good opportunity to make visual aids of levers and controls and dials.
try this 
www.logicmazes.com/dungeon.html
Does all the contents of the room have to remain static? New NPC's can't show up, for example?