It’s better not to do it that way. Making all spells available to everyone isn’t interesting. Each character in this game should be unique. You could simply divide magic into levels based on power. At the beginning, you come up with a few spells of the first level. The Game Master approves them and assigns numerical properties. For example, you want a phoenix, but at the first level, you’ll get a firebird with decent damage but weak defense. In any case, it will be weaker than your character. But a phoenix at level 5 magic could be much stronger than the character. If such an analogy is not possible, you will be asked to replace the spell. Also, as you gain levels, you can create your own spells. But not very often. There will also be a set of common spells that everyone can learn.