Source Adventurer’s Armory
These boxes feature moving parts, secret panels, or unusual codes and locking mechanisms. Depending on the box, a Disable Device, Knowledge (engineering), Linguistics, or simple Intelligence check might open it. The DC of the check varies with the complexity of the box but is typically 15 or 20 (retry once per day). Multiple skill checks might be necessary for different stages of the puzzle. If the puzzle box was constructed with the intention that one specific person should be able to open it, that person gets a +5 circumstance bonus on the check.