The Östener-Haal Limit

The Östener-Haal Limit manifests itself as a core law of biological beings capable of utilising magic. This limit stops the mortal body from producing enough mana to fuel spells beyond the defined "9th level". This limitation changes for all beings dependent on environment, heritage, and physical/mental training, and can be observed through autopsy as fluid-containing nodes, or "glands" as some have come to name them. As these nodes are depleted, magic becomes harder and harder to cast until the Haalimer Cycle comes into effect during respite.   Someone has become novice at the casting of magic, an apprentice mage, for example, has access to a small reservoir of their mana and only have the capability both physically and mentally to conjure spells that require small amounts of mana to be powered. As they practice these weaker spells, their ability to access greater and greater reserves of mana become second-nature, providing the necessary fuel to power their more complex magical incantations or empower simpler ones. Yet, certain mana reservoir limitations only allow for certain incantations to be accessed once per day or week, depending on their requirement for arcane fuel, such as 9th level magic requiring much more mana than a novice 1st level.   By casting a 9th level spell, such as Wish, the user uses their largest reserve to complete the incantation, retaining further mana nodes that are capable of fuelling spells of the 8th and lower tiers of magic. This just ensures that the largest, mortally-possible, "fuel cell" of spell-casting cannot be used again until the Haalimer Cycle is completed, disallowing users to cast lower tiered magic at the 9th level.

The Östener-Haal Limit is a universal law that governs all mortal creatures upon the world of Eurithan. This was imposed by the gods to ensure that no beings could dethrone them or become like them. Yet, there are areas in the world of Eurithan that have been struck with such untamed primordial energy that this limit tends to fail. This area scales the entirety of the continent of Anderall - a place so scarred from the Wars of the Colossus that godly limitations simply cannot invervene. This Anderallian Exemption allows some beings to breach the "9th level" and utilise magic that is so ancient that it defies common practice.