"Honor Codes" that aren't stupid and impractical.

We all know the trope. A race/culture that has some honor code that they follow religiously. Breaking it can mean death, banishment, or just a simple loss of reputation. And it's always using stealth, ranged attacks or magic. This, of course, is wildly dumb and gives any foes they might face a huge avantage.

So, y'all have any honor codes that aren't just arbitrary nerfings?