From Divinity Engine Wiki
- event CharacterUsedItem((CHARACTERGUID)_Character, (ITEMGUID)_Item)
Thrown whenever a character uses (player clicks on it, or character uses from story/script) an item.
- _Character: The character that used the item.
- _Item: The item that was used.
- If a player clicks on an item that causes a skill to be cast (such as a grenade, special arrow or scroll), this event will be thrown immediately. This means you get it even if the player then decides to cancel the actual casting by, e.g., right-clicking instead of left-clicking on a target.