Orbis Medeis has four main gameplay elements: Study, Spellcrafting, Spellcasting, and Practice.
Each element can be played up to three ways, and as per most things, a naturally adept player will have more luck than others.
In order for a player to be able to craft spells, they need sufficient knowledge in doing what they want to do.
Ergo, if the user wants to make a spell that can mine blocks, they need to mine a LOT of blocks.
If they want to make a spell that can harm entities, they need to harm a LOT of entities.
Likewise for moving, swimming, absorbing (bucketing) water, shooting arrows, alighting things on fire, lighting up blocks with torches/glowstone...