incantation not given
Makes an object unbreakable.
Hermione cast an Unbreakable Charm on the jar in which she imprisoned Rita Skeeter in beetle form (GF37).
incantation not given
The spell apparently cannot be performed using wandless magic (judging from Snape's remarks to Bellatrix rather than from the Weasley twins' underage efforts) and requires that the Bonder's wand be touching the joined hands of the person administering the vow and the person taking the vow. As each clause of the oath being sworn is agreed to, a thin tongue of brilliant red flame shoots from the caster's wand and winds itself around the joined hands of the participants, remaining in place as other clauses of the oath are sworn to.
Snape swore an Unbreakable Vow to Narcissa Malfoy with Bellatrix Lestrange as Bonder (HBP2).
The Weasley twins tried to get Ron to make one when he was about five, but Arthur caught them at it (HBP16).
Three curses in particular are known as Unforgivable because using them on another human being can result in a life term in Azkaban. These three curses were used extensively by Voldemort's followers during his rise to power in the 1970s, and their use by Aurors against suspects was in turn authorized by Bartemius Crouch senior at that time. One, the Killing Curse, was used by Voldemort himself on Harry Potter, but the curse backfired and Voldemort was defeated.
The three curses are:
Cruciatus Curse (see CRUCIO)
Imperius Curse (see IMPERIO)
Killing Curse (see AVADA KEDAVRA)
During the Battle of the Department of Mysteries, Harry tried to use the Cruciatus Curse on Bellatrix Lestrange, but it didn't have much effect. She taunted him:
"Never used an Unforgivable Curse before, have you, boy? You need to mean them, Potter! You need to really cause pain--to enjoy it-- righteous anger won't hurt me for long..." (OP36)
incantation not given
A magical effect on a place; makes it impossible to plot its location on a map.
Hermione suggested that this may have been done to make Durmstrang and Beauxbatons harder to locate by other witches and wizards (GF11).
Hogwarts also has wards and spells on it to hide its true nature from Muggles, but it is apparently not Unplottable.
The Room of Requirement is Unplottable, so that it doesn't appear on the Marauder's Map (HBP21).
Number twelve Grimmauld Place is Unplottable (OP6).
