Enspelled Staff (Level 4)

Bound into this staff is a level 4 spell. The spell is determined when the staff is created and can be of any school of magic. The staff has 6 charges and regains 1d6 expended charges daily at dawn. While holding the staff, you can expend 1 charge to cast its spell. If you expend the staff's last charge, roll 1d20. On a 1, the staff loses its properties and becomes a nonmagical Quarterstaff.

The spell's saving throw DC is 15, and its attack bonus is +7.