Spell Level: 3
Spell School: Abjuration
Casting Time: 1 Reaction (which you take when you see a creature within 60 feet of yourself casting a spell with Verbal, Somatic, or Material components)
Components: S
Range: 60 ft.
Area: None
Duration: Instantaneous
Conditions/Effects: Negation
Saving Throw: Constitution
Ritual: No
Scaling: None
Classes: Sorcerer, Warlock, Wizard
Link: Link to source
You attempt to interrupt a creature in the process of casting a spell. The creature makes a Constitution saving throw. On a failed save, the spell dissipates with no effect, and the action, Bonus Action, or Reaction used to cast it is wasted. If that spell was cast with a spell slot, the slot isn’t expended.