...legitimacy is based on three things. First of all, the people who are asked to obey authority have to feel like they have a voice--that if they speak up, they will be heard. Second, the law has to be predictable. There has to be a reasonable expectation that the rules tomorrow are going to be roughly the same as the rules today. And third, the authority has to be fair. It can't treat one group differently from another.
Malcolm Gladwell, David and Goliath: Underdogs, Misfits, and the Art of Battling Giants
authority, legitimacy, rules