Conduit Guardian Trap
Locked into the rock beneath this chest is a creature of stone that has waited for centuries fixed into a rectangular form. When the chest above it is opened the magic imprisoning the creature partially gives way and it rises to attack!
Conduit Curse. An attacker within 50 feet takes an equal amount of damage when it deals damage to the creature protecting the chest.
Spell Solve. Dispel magic (or any other effect that negates magic) and a spellcasting ability check deactivates the Conduit Curse and makes it appear as if the chest is untrapped. On a critical success, both the Conduit Curse and the effect binding the creature beneath the chest are dispelled (allowing it to peacefully go free).
Trap. This trap can be detected with an Investigation check to notice the unusual glyphs worked into the holy iconography of the chest. If the trap is not detected, it automatically triggers a critical failure.
With an Intelligence check to determine the chest’s approximate weight and a Dexterity check to swiftly swap it with an object of roughly the same size and weight (Small box, 35 pounds), the magic imprisoning the stone creature beneath it is fooled.
Critical Failure: The adventurers trigger the trap and are surprised as a stone monster (use the statistics of a stone giant with an Intelligence of 4; page 242 in Monstrous Menagerie) erupts from out of the floor to attack them.
Failure: As a critical failure but the adventurers are not surprised, or the adventurers activate the trap from a safe distance.
Success: The adventurers avoid or disarm the trap.
Critical Success: The adventurers avoid or disarm the trap but have the option to leave the trap active for someone else to deal with.