As the World Burns
The Chelish Crux
A cunningly designed puzzle-box, bigger on the inside
A Chelish crux is similar to a bag of holding in that its interior space is larger than its exterior would suggest. When closed, a Devil’s crux is a wooden and metal icosohedron (similar in shape to a d20) that measures about 6 inches in diameter. Each face of the crux is carved with a different rune or image — in order to open the puzzle box, a person must trace the outlines of these runes and images with the tip of a finger in the proper order. Each time a rune is triggered in the correct order in this manner, it glows with a soft red light.
Whenever a rune is triggered out of order, the light flashes into dangerous magical effects. and causes all lit faces to deactivate (forcing the process of opening it to start anew). Failure to open a crux eight times in a row causes the combination of runes to randomize to a new combination.
It might be theoretically possible to force a crux open, but it is likely that the crux has a defense against this possibility as well.
Once a particular crux’s combination is known, a character can open it automatically (this takes 3 consecutive full-round actions). Opened properly, the crux unfolds into a 2-foot-square flat sheet of metal and wood. Any objects the crux contains sit upon the center of the sheet. An unfolded crux automatically folds as soon as a character attempts to bend any of the sheet’s four corners as a move-equivalent action. The crux automatically folds up around any objects that sit upon its face at this time — objects that would exceed the crux’s capacity are pushed gently aside by the refolding action.
A Devil’s crux can hold up to 200 pounds of objects, but the physical size of each object is irrelevant — the sight of a crux folding up around a long polearm, for example, might make one assume the weapon was crushed and destroyed, but when the crux is next opened, the pole arm is unharmed. As an object that creates an extradimensional space, a Devil’s crux functions as a bag of holding for determining how long a living creature within can survive, or for what happens when the crux is placed in another extradimensional object like a portable hole.