Periculum was a charm that allowed the caster to send out red sparks from their wand. The sparks were firework-like in appearance, and had a vast range, shooting up to a great height, then hovering in the spot where the caster aimed. Much like a Muggle flare gun, the spell was used to signal that one was in danger, and thus in need of help.
- Minerva McGonagall instructed the four champions to send red sparks into the air if they needed to be rescued prior to the Third Task of the Triwizard Tournament in 1995. Harry used this spell when Fleur Delacour was being dragged into the maze. Later on, at the urging of Harry Potter, Cedric Diggory used this spell to send red sparks into the sky to call the Hogwarts professors to rescue Viktor Krum, who had been Stunned by Harry after he attacked Cedric whilst under the Imperius Curse set upon him by Barty Crouch Jr. (when he was impersonating Alastor Moody).
- Periculum is Latin for "danger".
- Harry Potter and the Goblet of Fire (First appearance)
- Harry Potter and the Goblet of Fire (film) (First identified as Periculum)
- LEGO Harry Potter: Years 1-4