Copper Dragon's Trickery

You curse a foe with mishap, which strikes whenever it slips up. When you cast this spell, you can choose a creature you can see within range. At any time before the spell ends, when the target of this spell makes an attack roll, you can use your reaction to curse the first attack roll made by the target that turn. If this attack misses, then the target must make a Dexterity saving throw or fall prone. The target can't stand up from being prone until the start of its next turn.

I had Permission from Nielspeterdejong to transcribe his magic to DnD beyond