YAOSC (Yet Another Old School Clone)
If trained in this skill, you can trigger magical effects built into a magic item. Many such devices can be triggered by an act of will; check this skill for characters trying to assert control over devices that they are handling for the first time. (In case of failure, the character must gain an experience level or learn significant new information about the device before trying again.) Often the nature of the enchantment causes involuntary reactions in the wielder, such as giving voice to a Word of Power or acting out a gesture.
Some devices actually require knowledge of a command word or other secret, or even rapport with a resident spirit or intelligence, before they can be used. Some abilities of magic weapons may be treated as device powers.