Learning magic above level 3 requires learning related skills. For example, if you learn basic/advanced/expert summoning, you can learn summoning magic at level 3 /4 /5 and other magic.

Branch skills of learning witchcraft: Insight into magic allows heroes to learn level 3 magic without restriction, regardless of whether they have learned related skills.

If a hero learns to gain insight into magic and has the power of a treasure, he can learn level 4 magic without restriction, regardless of whether he has learned related skills or not.

Adventure magic is a little different:

Salazar's boat

Hero level 1 is required (skill support is not required). Heroes can learn by visiting towns with secondary magic guilds.

Summon creatures

Hero level 10 is required (skill support is not required). Heroes can learn by visiting towns with third-level magic guilds.

Two-dimensional journey

Hero level 15 is required (skill support is not required). Heroes can learn by visiting towns with level 4 magic guilds.

Town shikong gate

Heroes need level 20 (no skill support), and heroes can go to towns with level 5 magic guilds to study.