Summoning Charm

"Hermione: Your wand, Harry!

Harry: Accio! "

-Harry Potter and Hermione Granger in 1994

The Summoning Charm (Accio) is a spell used to summon an object toward the caster. It is taught to students in grade four at Hogwarts School of Witchcraft and Wizardry. The farther the caster is from the target, the more difficult it is to summon it. However, there is some controversy on this claim, as Hermione Granger once stated (in the short film the Queen's Handbag) that it doesn't matter how far away you are from the object; so long as you know what it is you wish to summon, you should be able to summon it with ease.

There are, however, spells that can be placed which prevent an object from being magically Summoned; the incantations and names of these spells are currently unknown.