Banned Spells
Unable to be used by anyone
PS: Spells marked by () are spells whose proper name or pronunciation are not given in canon.Avada Kedavra - Banned for being overpowered and for IC reasons that will be explained later.
(Albus Dumbledore's forceful spell) - Banned for being overpowered.
(Horcrux Curse) - This one is banned for rather obvious reasons.
Sectumsempra - Banned for in character reasons, as IC there is no way of learning it.
Limited Spells
Able to be used only with admin permission or if certain conditions are met.
(Anti-Disapparition Jinx) - Only with admin permission, and being either a B or higher ranked rogue wizard or a teacher.
(Antonin Dolohov's curse) - You must be a B or higher ranked wizard, have admin's permission and only usable if victim is under submission i.e. kidnapped.
(Apparition) - Apparition is impossible in areas with the Anti-Apparition and Anti-Disapparition Jinx. Only for students of 17 years of age or more(No need to be in the seventh year, but at least at the fifth). Player that attempt it before reaching said age and are not doing it with assistance of someone who does will be either have their apparition voided or have "accidents".
Avifors - Items that can be targeted are limited to small objects such as little statues and vases, for example. Not possible to execute in wands. The exception is if one is the Transfiguration teacher, still, this spell can't be used offensively.
Crucio (Cruciatus Curse) - Limited to at least B-Ranked rogues or 7th year students, and when used, the user instantly becomes a rogue wizard. If used for killing, it takes about four posts to kill someone with Crucio, under frequent use and no interruptions or distractions whatsoever.
Expecto Patronum (Patronus Charm) - Limited to 3rd Year studens or with admin consent.
(Fidelius Charm) - Only possible to use with admin consent.
Fiendfyre - Only possible to use with admin consent, and sixth year or above.
(Firestorm) - Limited to graduates or B-Ranked rogues.
Imperio (Imperius Curse) - Limited to at least B-Ranked rogues or 7th year students, and when used, the user instantly becomes a rogue wizard.
(Molly Weasley's Curse) - It doesn't kill, it turns the target into stone, and is only usable with admin consent.
Obliviate (Memory Charm) - Only possible to use with admin consent.
Portus - Only possible to use with admin consent.