Item from Worm by Wildbow
The informal code that governs parahuman conduct — don't reveal secret identities, don't target families, don't kill if you can avoid it. Honored more in theory than in practice.
The unwritten rules are Brockton Bay's — and Earth Bet's — fragile social contract between capes. They were never formally codified, but they're understood by everyone in the community: you don't reveal another cape's civilian identity. You don't target their family. You don't use lethal force unless the other side does first. Villains and heroes maintain a tacit understanding that the cape game has boundaries, because without those boundaries, every gang war becomes an assassination campaign and every arrest becomes a witch hunt. In practice, the rules are elastic. The Empire breaks them selectively. Lung doesn't care about them when he's ramping. Coil operates entirely outside them because no one knows who he is. The Protectorate enforces them officially and uses the threat of Birdcage — the inescapable parahuman prison — as the ultimate deterrent for capes who go too far. For a new cape, the unwritten rules are the first thing you need to learn and the first thing you'll see broken. They're the difference between a cape scene that's dysfunctional and a cape scene that's apocalyptic.
Also known as: the unwritten rules, cape rules, the rules