Overview

An object was called toward the caster by the Summoning Charm (Accio). By summoning the object out loud following the incantation, it could call forth both objects in the caster's direct line of sight and objects that were out of sight (unless the magic was cast nonverbally).
This spell required careful planning, and before attempting to call it forth, the caster needed to have a clear mental image of the thing. The spell would be useless if there was any distraction.
The Banishing Charm was the reverse of the Summoning Charm.

Effects

Buildings were not suitable targets for the Summoning Charm. Furthermore, it wouldn't work on living creatures, albeit they may be indirectly moved by calling forth objects they were holding or wearing. Since they traveled at nearly the speed of light and may be hurt in the process, calling them in this way was dangerous. Flobberworms, which were typically not thought to be worth calling, were the sole known exception to this rule.
It was more difficult to call forth an object that was farther away from the caster. But according to Hermione Granger, no matter how far away the object was, the caster should have no trouble calling it forth as long as they had it in mind. Furthermore, the object cannot be summoned unless its broad location is known.
It was possible to apply counter-spells to objects to prevent them from being called forth. The majority of wizarding items on the market in the 20th and early 21st centuries were pre-enchanted with an anti-theft enchantment to prevent anybody other than their legitimate owners from calling them forth.
The high level of defenses placed on horcruxes also made it impossible to summon them in any form, as demonstrated by Hermione's unsuccessful attempts to summon Ravenclaw's Diadem, Slytherin's Locket, and Hufflepuff's Cup.

History

One of the earliest recognized charms in wizarding culture was the Summoning Charm. Miranda Goshawk claims that the Accionites and their leader, Gideon Flatworthy, were the most well-known users of this spell.

The son of the pot's original owner called forth a misplaced donkey that belonged to one of his fellow villagers in the classic wizarding story "The Wizard and the Hopping Pot" from The Tales of Beedle the Bard.

This charm was taught to fourth-year students in the Charms course at Hogwarts School of Witchcraft and Wizardry. It was then rewritten for a fifth-year student in order to get ready for O.W.L.s. Before they used the charm in a Summoner's Court game during the 1890–1891 academic year, Professor Abraham Ronen had his fifth-year students go over it. This spell was found in Miranda Goshawk's The Standard Book of Spells, Grade 4.

Using this spell in conjunction with the Slowing Charm, a Calamity Investigator with the task force harvested hair from even the fastest Granian winged horses during the 2010s Calamity. In order to shorten the brewing time for their Exstimulo Potion, the researcher discovered that the hair of exceptionally fast Granians was even more powerful.

Credits/References

Written by Desmond Gray
Base code by Andrew Sutherland, edited by Iselin Merilä and Desmond Gray.