You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 4th level or lower, it has one of two effects:

1) If the spell has the "buff" spell effect tag, it is cast on you.

2) If the spell does not have the "buff" spell effect tag, it is cast on the creature that casted the spell. If it is an area of effect spell, it is centered on the creature.

If it is casting a spell of 5th level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a success, the creature's spell fails and has no effect.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the interrupted spell has no effect if its level is less than or equal to the level of the spell slot you used.