The Last Hearth has no classes. Instead you swear Oaths — promises to a faction, a person, or an idea — and the world holds you to them. There are five, and you cannot keep all five, because they contradict each other by design. Before any of this touched code, it lived on paper. We wrote each Oath as a sentence a character might actually say, then asked the only question that matters: what happens when you break it? An Oath the game forgets is just a menu. An Oath the game remembers — one that changes what your companions say, what merchants will sell you, which endings are still on the table — is a relationship. This post is mostly design, not engineering, because the engineering only makes sense once the fiction does. We would rather find out on paper that an Oath is boring than discover it three systems deep. The next pass turns the five sentences into state the world can read.