Expelliarmus

To cast this spell, the user must shout its name while pointing his or her focus at their intended target. On a hit, the target must succeed on a strength saving throw against the spell caster's spell casting DC. On a failed save, the weapon or item the target is holding is pulled from their hand towards the caster, flying in a straight line for 10 feet. If the object would impact the caster, the caster can make a DEX save of 10 to avoid the object.

If the object or weapon impacts the target,the target takes damage. For a weapon, roll the appropriate die for the weapon. For an object, the caster takes 1D4 if hit.