Spinning Cylinder Trap CR 10
This entire chamber is composed of a highly polished alloy of ferrous metals and forms a giant Halbach cylinder with its magnetic force pulling toward the outer wall. Anyone entering the chamber finds that items of ferrous metal are immediately drawn toward the nearest wall. Any such item weighing 5 lbs. or more is capable of pulling its possessor across the smooth-polished floor unless they are able to anchor themselves in some way or make the appropriate Strength check each round (DC 15 + 2 for every additional 5 lbs. [or fraction thereof] the metal object weighs). All metal gear carried by a PC is considered a cumulative total for this Strength check. A character that slides into the room from the brass slide does not have the opportunity to make this Strength check to avoid becoming pulled to the wall, as his momentum carries him directly into the wall.
One round after the first PC enters the round, a curving section of wall rises into place across the entry slide (on Initiative rank 0), closing off the chamber in a complete cylinder. An instant later, the entire room spins counterclockwise around the spindle. Even those not magnetically attracted to the wall must make a DC 20 Reflex save each round to avoid being pushed to them by centrifugal force unless flying or anchored in place in some way. The DC of the Strength check to pull metal items loose for those adjacent to the outer wall while it is spinning is increased by 5. In addition, all attempts at spellcasting require a DC 20 + spell level Concentration check to successfully cast and all attack rolls suffer a -20 circumstance penalty.
The room continues spinning until the trap is disabled, the way to the slide is somehow opened (treat as an iron wall), or there are no more living creatures in the chamber. In theory it can spin for ages, ceasing only once its victims have died of thirst. Once one of these conditions is met, the room ceases spinning and the wall to the slide opens again. The trap can only be disabled from the central spindle (which does not spin with the rest of the room), so a PC must make his way to it in order to attempt to do so. A successful Search check must be made on the spindle before an attempt can be made to disable it.
Type mechanical; Perception DC 25; Disable Device DC 25
Trigger location; Reset automatic
Effect magnetic walls, spinning chamber (see above)