Staff of Striking

You have a +3 bonus to _attack and damage rolls_ made with this magic quarterstaff. When you hit with a melee attack using this staff, you can expend up to 3 of its charges, dealing an extra 1d6 force damage per expended charge. The staff has 10 charges and regains 1d6+4 expended charges each dawn. When the last charge is expended, roll a d20\. On a 1, it loses its magical properties.