I have created a magical dagger that can paralyse people, that I plan to give to the party when they reach roughly 10th level. Is it balanced?
Dagger of Paralysis
Weapon (dagger), rare
This is a +2 magical weapon. When you attack a target and hit with that attack, you can expend one charge of this dagger to cause the target to make a Constitution saving throw (DC 18). On a failure, the target is paralysed for 1 minute. The target can repeat the saving throw at the end of it's turn, ending the effect on a success.
This dagger has 3 charges, which reset at dawn. If you use the last charge, you must firstly make a Constitution save (DC 18) or be paralysed for 1 minute. You cannot repeat this save. Secondly, you must roll a d20. On a 1, the dagger is magically transported to a random spot on the material plane.
Best Answer
It is too powerful
Same rarity as a vanilla +2 weapon, but can be used twice a day quite reliably to paralyse someone. (You should be very desperate to use the third charge)
Only a dagger can have this enchantment, and this limits the DPR, but I still think it does not offset the huge control potential.
I would either decrease the save DC to around 15, or give it only +1 for attack and damage.