The Three-Fold Law Of Return
"Mind the Three-fold Law, ye should.  Three times bad and three times good."
Any spells you cast that is not on yourself will come back 3 times full.

If it's a "good" spell, it will come back to you 3 times better.

If it's a "bad" spell, it will come back to you 3 time worse.

Now that also depends on the  intentions in your heart.  So be careful.  Be true hearted.

It is
NOT a good thing when you do a spell only with the intentions (or even the thought) of u getting anything in return.  That does nothing but harm yourself, and/or weakens the spell.