Karma and free will in Advaita Vedanta, plainly

Karma, at its plainest, is a cause-and-effect principle applied to action: intentional actions produce results, and those results shape the circumstances and tendencies you encounter later. It's not a claim about fixed, unchangeable fate — it's closer to "your choices have consequences, including consequences you don't see immediately," which is a fairly ordinary idea once it's stripped of mystique. Advaita Vedanta takes this fully seriously at what it calls the vyavaharika level — ordinary, everyday, transactional life. Within that level, your effort matters, your ethical choices matter, cause and effect operate exactly as they appear to. Advaita is not a teaching that tells you actions don't matter or that trying is pointless — quite the opposite; a whole tradition within Vedanta, karma yoga, is specifically about acting fully and responsibly in the world. The distinctive move Advaita makes is at the other level, the paramarthika or absolute standpoint. There, the argument goes, karma applies to the jiva — the individual person, bound up with a particular body and mind, the one who experiences themselves as a doer making choices with consequences. It does not apply to the Atman, the deepest self, because the Atman — as pure awareness, not a doer, not an agent, not a thing that acts — was never actually the one doing anything in the first place. Action happens within the field of body and mind; awareness itself, in this teaching, simply illuminates that it's happening, the way light illuminates a room without the light itself doing the moving around inside it. The practical teaching most commonly drawn from this — especially associated with the Bhagavad Gita — is to act fully, carefully, and responsibly in the world, while holding the results more lightly than the effort: give the action your full attention, and hold the outcome without the same grip, since your deepest nature was never actually the anxious owner of that outcome to begin with. That's presented less as detachment from life and more as a different relationship to it — full engagement without the constant self-referential anxiety of "what does this mean for me."