Glacius

• Incantation: Glacius
• Pronunciation: GLAY-see-us
• Wand Movement: Unknown.
• Light: Typically a jet of pale blue or white light (video game).
• Effect: A freezing spell that encases its target in ice, immobilizing creatures or freezing liquids.
• Type: Charm

The `Glacius` charm is not mentioned in the seven original *Harry Potter* novels. Its existence and use are primarily established within the continuity of the *Harry Potter* video games.

• In the Harry Potter and the Prisoner of Azkaban video game, the spell is taught to Harry Potter, Ron Weasley, and Hermione Granger. It is used extensively for puzzle-solving, such as freezing bodies of water to create ice slides, and for combat, specifically to extinguish and immobilize fire-dwelling salamanders (video game).
• In the Harry Potter and the Goblet of Fire video game, `Glacius` functions as a combat spell used to temporarily freeze enemies like Erklings and salamanders, making them vulnerable to attack (video game).
• In the Hogwarts Legacy video game, `Glacius` is taught to the protagonist by Madam Kogawa as a reward for a flying assignment. It is categorized as a control spell that freezes enemies, increasing the damage they take from subsequent attacks (video game).

As the spell does not appear in the novels, its place in the standard Hogwarts curriculum is unknown. In the video games where it features, it is typically learned as part of the game's progression. There is no officially stated counter-spell in any source material. However, it can be logically assumed that a fire-making spell, such as `Incendio`, or a general `Warming Charm` would be effective at melting the ice produced by `Glacius`. In some game mechanics, the freezing effect simply wears off after a short period.

The incantation `Glacius` is directly derived from the Latin word glaciēs, which means “ice.” The related Latin verb glaciō means “I freeze” or “I turn to ice.” This etymology is reflected in English words such as “glacier” and “glacial,” all relating to ice and freezing temperatures.

`Glacius` is one of the most prominent spells created for the *Harry Potter* video games, designed to provide players with a specific gameplay mechanic. It serves a dual purpose as both a utility spell for environmental puzzles (e.g., creating ice bridges) and a combat spell for crowd control (immobilizing foes). Its visual effect in the games is consistently portrayed as a beam or jet of icy blue or white energy that causes ice to form rapidly on its target. While it did not originate in the books, its inclusion in numerous games, including the recent and expansive Hogwarts Legacy, has made it a well-known spell among fans of the wider Wizarding World franchise.