# Magical items after all charges used [duplicate]

Running a campaign for the first time (first time for players and for me) and of course I am running Lost Mine of Phandelver. My players are about to confront Glasstaff and I had a question about the staff of defense he holds. Do players and their characters know that if they use up all the item's charges there is a chance it will be destroyed?
I am writing the item description on the card to give to the player and I wasn't sure if if should include the "roll a d20 after all charges, if 1 item destroyed".

I suppose there are 3 ways:

1. They know immediately upon attuning.
2. They can take it to someone to know more about it
3. They will never find out until the day they roll that 1