The material below is Open Game Content
Trap: The obelisk is a giant lodestone whose magnetic properties are activated when more than 30 pounds is applied to any one of dozens of pressure plates on the chamber floor. The abbot alone knew the safe path through the chamber, which involves skirting the circumference west and then cutting a path east after passing the obelisk and looping back south to the eastern exit.
Anyone stepping on a pressure plate unleashes a magical discharge of energy and takes 1d6 electricity damage. This charge also activates the powerful magnetic quality of the obelisk. The entry doors are yanked shut and jammed by the magnetic pull, just as those over the alcoves are wrenched open. Anyone wearing metal armor is dragged 10 feet toward the central obelisk every round (DC 10 Strength check to resist this pull, DC 15 Strength check to move normally, although half speed away from the lodestone). Once pulled to the obelisk, such characters are pinned (as in a grapple). Success on a DC 10 Strength check is required to take any action, and a 15 on the check allows a character to pull free of the obelisk. Metal objects secured on a person are ripped free and cling to the obelisk.
Metal objects gripped (shields or weapons) are wrenched from the hands of anyone failing a DC 10 Strength check (even if this check is made attacks made with held metal weapons have a –2 penalty). The lodestone retains its magnetic quality for 1d4 minutes but can be deactivated earlier if it is struck with a second electrical discharge.
Lodestone obelisk Trap CR 2
Type magic device; Search DC 21; Disable Device DC 21
Trigger location; Reset automatic
Effect shocking grasp (1d6 electricity damage) and activate obelisk