You attempt to interrupt a creature in the process of Casting a Spell. If the creature is Casting a Spell of 3rd Level or lower, its spell fails and has no Effect. If it is Casting a Spell of 4th 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 4th 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.