- "“Reducio,” Moody muttered, and the spider shrank back to its proper size."
- —Moody countering his own Engorgement Charm.[src]
- In 1994 Barty Crouch Jr. (disguised as Alastor Moody), who had enlarged a spider with an Engorgement Charm, used this to return it to its normal size.
- In 1998 Harry Potter was having trouble with this charm along with the Engorgement Charm when casting them upon a spider in order to practice with the blackthorn wand Ron had won from a group of Snatchers. His attempts were feeble since he was not the real master of the wand.
- Harry Potter may have used this spell unintentionally to shrink an ugly sweater of Dudley Dursley's when Petunia Dursley was trying to force it over his head.
- In 1994 when Hermione Granger's teeth were enlarged by the Densaugeo jinx accidentally by Draco Malfoy, Madam Pomfrey probably used the Shrinking Charm to return her teeth back to normal size, though Hermione took advantage of this situation and allowed her teeth to be shrunk to less than their original size. Up until this point she was always said to have "rather large front teeth."
English reduce, "to shrink". (Latin has a verb reducere, present tense reduco. This is the source of the English "reduce", but has a different meaning.) Also in Italian Riduco first person present tense of Ridurre, same root of Latin Reducere.
Behind the scenes
- In Harry Potter and the Deathly Hallows: Part 1, the scene where the spider is enlarged is replaced by one of Hermione's bluebell flames.
- The effects of this spell bear great similarity to the spell Diminuendo, and the two spells may be variants of each other.
- A possible difference between the effects of the spells may be that Diminuendo shrinks objects to be smaller than their original size, while the Shrinking Charm acts as a counter-charm for the Engorgement Charm, shrinking objects back to their original size after being enlarged by the Engorgement Charm. The Shrinking Charm has always been coupled with the Engorgement Charm in the books (for cases where it is clear that the Shrinking Charm is used and not other shrinking charms).
- Harry Potter and the Philosopher's Stone (Possible appearance)
- Harry Potter and the Goblet of Fire (First appearance)
- Harry Potter and the Deathly Hallows
- Harry Potter and the Deathly Hallows: Part 1
- Wonderbook: Book of Spells