Here is my Alignment system, spelled out:
Alignment
Characters typically begin play with an Alignment roughly similar to the culture they came from. Thus, most Backgrounds will generally provide Skill proficiencies that orient towards a particular Alignment.
These Alignment background orientations are meant for inspiration, not as hard-and-fast rules. Heroes by their nature break the mold, and can begin play with any imaginable combination of background skills.
Unaligned
Many mortals live their lives without considering any of the four cardinal Alignments, or dedicated Neutrality. Such characters may have a tendency towards one Alignment or another - characters from a highly technological society will tend towards the Arcane over the Primal, for example - but they don’t have any particularly strong views one way or the other.
The Unaligned classes are the Fighter, the Rogue, and the Sorcerer. An Unaligned character typically lacks the dedication to devote themselves to any Alignment in particular.
Arcane
Characters with an Arcane alignment typically come from cultures that prize technology, progress, and material wealth over ecological balance and sustainability. They have decided that the benefits of technology - advanced medicine, abundant food no matter the season, comfort and shelter even in the face of disaster - easily outweigh the costs. A character from such a culture will typically hold onto these assumptions subconsciously, even after months or years away from their culture’s direct influences.
The Arcane classes are the ???, Artificer, and Wizard. An Arcane-aligned character can also be Divine or Eldritch aligned, but their intuitions and assumptions are incompatible with the Primal alignment.
Primal
Primal cultures value sustainability and ecological balance over technology, progress, and material wealth. They have decided that the costs of technology - ecological damage, wealth inequality, and alienation - are too high for the benefits and conveniences it offers. A character from such a culture will often subconsciously maintain these assumptions even after months or years away from their culture’s direct influences.
The Primal classes are the Barbarian, the Ranger, and the Druid. A Primal-aligned character can also be Divine or Eldritch aligned, but their intuitions and assumptions are incompatible with the Arcane alignment.
Divine
Characters with a Divine alignment often come from cultures that prize social cohesion, cooperation, and conservative stability over individual expression and freedom. They have decided that their culture’s social mores and customs are integral to the fabric of their society, and that flouting them is dangerous - even for seemingly good reasons. A character from such a culture will typically hold onto these assumptions subconsciously, even after months or years away from their culture’s direct influences.
The Divine classes are the Paladin, the Inquisitor, and the Cleric. A Divine-aligned character can also be Arcane or Primal aligned, but their intuitions and assumptions are incompatible with the Eldritch alignment.
Eldritch
Characters with an Eldritch alignment often come from the same cultures as Divine-aligned characters, but found the expectations and restrictions of their culture stifling. An Eldritch-aligned character values their freedom of expression too highly to conform to any particular social mores, and will often rebel against any demand for conformity on mere principle. A character from such a background will typically hold onto these assumptions subconsciously, even after months or years away from their culture’s direct influences.
The Eldritch classes are the Herald, the Occultist, and the Warlock. An Eldritch-aligned character can also be Arcane or Primal aligned, but their intuitions and assumptions are incompatible with the Divine alignment.
Mystic
Mystic characters emphasize balance in all things, and carefully weigh the benefits and drawbacks of each choice they make. A particular choice, whether it leans towards Primal, Arcane, Divine, or Eldritch values, will be weighed against all other possible choices, with the concerns of each perspective carefully weighed and considered. The truly neutral alignment that Mystics value is more difficult to practice than any of the four extremes.
The Mystic classes are the Monk, the Bard, and the Sage. A Mystic character is always Mystic, but they can understand the perspective of any of the other alignments.