"Play by the rules! No cheating, children!"
—Grindelwald to the Aurors attempting to flee from his spell[src]

Protego Diabolica is the incantation of a powerful protective dark charm. It allows the user to conjure a protective ring of black fire around them that completely incinerates enemies of the castor who come into contact with it, while leaving their allies unharmed.[1] In 1927, Gellert Grindelwald cast this spell in the Lestrange Mausoleum to test the loyalty of his followers and kill a number of his enemies.[2]

Casting and effects


Grindelwald controlling the fire to separate his enemies from his allies

When cast, Protego Diabolica creates a ring of black fire around the caster.[2] It is possible to walk through the flames unharmed, as demonstrated by Vinda Rosier, Credence Barebone, Queenie Goldstein and Abernathy amongst others, if they are loyal to the caster and mean them no harm. However, Krall, who earlier expressed doubt about Grindelwald's goals, was burnt to ash within a few moments of entering the fire.

Grindelwald was also seen controlling the spell as a weapon by causing tendrils of black fire to extend from the ring and burn his enemies, some of whom were in the process of apparating. The tendrils can be deflected or blocked, temporarily, with the Shield Charm.

Grindelwald was able to use the ring of fire in an attempt to destroy Paris. The fire soon manifested what appeared to be a fiery winged demon within it as it spread and burnt everything in sight, similar to the effects of Fiendfyre. It was so powerful that it required the combined usage of the General Counter-Spell by Newt and Theseus Scamander, Tina Goldstein, Nicolas Flamel and a number of others.

Known practitioners


  • The incantation comes from Latin "protego", "I protect", and "diabolica", a declension of "diabolicus", meaning "diabolic, relating to the Devil".

Behind the scenes

  • In Fantastic Beasts: The Crimes of Grindelwald - The Original Screenplay, the spell creates a "circle of black fire", whereas in the film the flames are bright blue.
  • The spell's trait of rapidly spreading and growing in size and being able to create bestial entities out of its flames is remarkably similar to Fiendfyre, suggesting the spells are related. Additionally, the spell shares similarities to Bluebell Flames, which can seemingly be made to only damage certain targets and objects, as well as the caster being able to direct its movement to an extent.


Notes and references