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.
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.
If the spell was cast using a spell scroll, the spell still fails but the spell scroll is not expended. If the creature's spell fails and it would have expended a spell slot, it may make an ability check using its own spellcasting ability. The DC also equals 10 + the spell's level. On a success the creature's spell fails and has no effect. On a failure, the spell slot is lost.
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.