Staff of Withering

This magic quarterstaff has 3 charges and regains 1d3 expended charges each dawn. When you make a successful _melee attack_ with the staff, you can expend 1 charge to deal an extra 2d10 necrotic damage. The target makes a DC 15 Constitution _saving throw_ or for the next hour it has _disadvantage_ on Strength and Constitution checks and saving throws.

Source: Level Up Advanced 5e · OGL-1.0a · 5.1