Shrinking Maze

Introduction: A gradually shrinking maze that herds the PCs towards a final room.

Setting/System: Setting could be anything pretty much, though the exact nature of the maze would need altering to suit. There are no particular system requirements for this one either.

Description: This is a series of large tunnels, wide enough for two people to easily walk abreast (working in D&D measurements, each square on the map is 10 feet). The tunnels are featureless and made from stone/metal/plastic (as appropriate to the setting); if the tunnels are not featureless, they should at least be homogenous… if there are blinking LEDs or something, they should be everywhere.

Mechanics: There are no special mechanics for the tunnels themselves, though they could certainly have traps and other things present. However, the overall maze has one special mechanic…
Every time the party crosses from one coloured area to the next, doors close across the corridors and completely cut off the old colour from the rest of the maze. In this way, the maze gradually shrinks, as the PCs approach the centre. The maze is smart enough to know when the entire party has entered the next “ring” (either through magic or external monitoring), so they will never be split up in this way. The doors that close appear exactly the same as the walls; once closed, the tunnel simply appears as a dead end.

Encounter: There are two ways to play this maze. Firstly, the doors could close the second the last PC steps over the line. This will likely lead to them attempting to re-open the door; personally, I would squash the idea fairly quickly so they don’t waste time on it (the door is too big and heavy to move and there are no obvious controls). The second option is to have a slight delay, so that the players don’t know the tunnel has closed off until they try and backtrack.
Within the maze itself, there should be small encounters periodically; either insert some traps or small guard patrols. These should not be too tough, as the PCs have no real option for retreat… they need to make it to the centre intact.
The centre room is the focal point of the maze and could be pretty much anything; a treasure room, the site of a ritual that the players need to stop, a portal to another location entirely. Whatever might be found there, there needs to either be a way to reset the maze or an alternative way out, so that the PCs can leave when they’re finished.