Our starting point for this town and surrounding lands
There are strict civil laws about magic, both clerical/druidic and wizardly. These laws rose out of a profound misuse of magical power many hundreds of years ago.
A crown-issued permit is required to perform magic beyond a certain level of potency, to receive advanced training or guidance to be able to perform such powerful magic, or to create any magical items that would be equally potent. Those who have a permit must comply with an auditing process every so often to ensure that they have not attempted to exceed the bounds of their permitted activities. The existence of these strictures is well known, and people who witness forbidden acts of magic may require convincing (e.g. bribes, coercion) not to report this. As you travel, you will undoubtedly discover that it is easier in some places than others to get away with this kind of thing.
Magic of lesser potency (i.e. simple enough not to be regulated) is uncommon but normal (i.e. normal D&D level, PCs and adventuring NPCs will include spellcasters) and does not require permitting.
Magical items of some kinds are thus also fairly rare. The magical items that do exist tend to be one-use or limited-use items (like potions and scrolls). During The Cleansing (when the laws were enacted, etc.) most significant magic items were rounded up and demagicked — at least, that is what everyone knows to be true.
Given that their magic doesn't derive exactly from continued study, Sorcerers are considered automatically suspect and must register with the crown. Newly-identified Sorcerers are typically taken in as wards of a state-sponsored Wizard. Warlocks and the kinds of contracts they make with other-worldly powers are forbidden by law and are subject to execution.
For clerics and druids, the religious order is charged with keeping track of progress and adherence. Clerics and druids "in danger" of advancing too far are expected to be brought in and cloistered for closer monitoring. One would expect that in some cases paperwork is carefully annotated to allow selected non-adherence; this would vary by order and by province within the order.
For wizards, in most areas there is a guild system and the acquisition of new spells (i.e. to be written in the spell book) is the most effective way of gate-keeping magic acquisition. In less populated areas, these responsibilities may fall on the geographically closest wizard of rank. Again, illicit acquisition may occur but would be unacknowledged.
For sorcerers, they are assigned to a wizard of rank to monitor them. An annual report of progress is meant to be filed with the wizard's guild. The guild reserves the right to inspect progress at any time.
Bards are uncommon (but you are welcome to pick one as your character) — they would probably be treated as sorcerers given how they "get" their magic. Paladins and rangers would be treated as clerics and druids respectively.
The strictures are somewhat parochial in enforcement and interpretation but everyone believes that there is agreement in the philosophy of the strictures that extends to all known lands (i.e. the entire continent, which may or may not include the island).
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