'The Renaissance of Natural Law: Tolkien, Fantasy, and Video Games' by Edward Castronova considers the moral systems that designers create inside video games -There's much similarity across games, despite wide differences in narratives, backgrounds, target demographics, and mechanics. Using the terms of Dungeons & Dragons morality, most games have three moral factions: Lawful Good, Chaotic Good, and Chaotic Evil. Players usually get to choose between Lawful or Chaotic Good, while the AI plays Chaotic Evil. Now, why does this pattern appear so frequently? I'll argue it has something to do with Natural Law. Natural Law derives moral judgment from the notion that any reasonably well-formed human mind can discern what the purpose or end of an item is: What it's for. It's a common-sense morality, which may or may not work well in advanced bioethics but suits the moral world of video games perfectly, where bad guys are really easy to identify but the players fight back and forth about whether to be a rule-following hero of light or a renegade, rebellious, dark angel. That law/chaos tension is also an aspect of Natural Law. As for how Natural law got into games, the path seems to run through JRR Tolkien - devout Roman Catholic and therefore no stranger to the teachings of Aquinas. From Aquinas to Tolkien to D&D to modern video games, the LG/CG/CE triangle persists as a simple moral world, but one that, judging from player numbers, people very earnestly want to live in. Is this in itself a good thing? Since we're talking Natural Law, let's conclude by asking - what is the purpose of fantasy? Does this usage suit fantasy's purpose?