Counterspell

Counterspell PHB p228 3rd-level abjuration Casting Time: 1 reaction, which you take when you see a creature within 60 feet of you casting a spell Range: 60 feet Components: S Duration: Instantaneous 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. Classes: Sorcerer, Warlock, Wizard Subclasses: Arcane Trickster Rogue, Eldritch Knight Fighter, Redemption Paladin, Watchers Paladin Races: Human (Mark of Sentinel) Backgrounds: Azorius Functionary Source: PHB, page 228. Available in the SRD and the Basic Rules.