Obviously, when you have a large number of people walking around in colossal death machines, you’re going to need a few ground rules.
The Cavalier’s Code is an honor system followed by cavaliers. It regulates many aspects of the job such as combat and employment. There are several local variants, such as the Crihna Rede and Neo Duello, but they all have the same basic structure. A copy of the rules can be found at most cavalier clubs and arenas.
Most of the rules deal with the use of deadly force. To minimize damage, there are several restrictions placed on where and when cavaliers are allowed to fight. Attacking civilians is forbidden. Attacking a cavalier who is not prepared for combat is also forbidden. Battles must begin with a formal challenge. Note that the definitions of “prepared for combat” and “formal challenge” are pretty loose- if a cavalier is awake and inside of a mecha, they’re fair game. Also note that local laws may place further limits on mecha combat; in general, it’s illegal to challenge someone within city limits.
Next are the rules regarding contracts and employment. It’s important that employers can trust cavaliers, otherwise there’ll be fewer jobs for everyone. Once you agree to a contract or a duel you must honor your word. If you enter a long term contract, you may not refuse missions from your employer. Renegotiation may be possible if the situation changes.
Cavaliers have a duty to protect those in need. Cities allow cavaliers to operate within their borders knowing that in case of attack, those cavaliers can be rallied to defense. You are expected to aid those who provide you with food, lodging, and repair. Failure to do so is not strictly forbidden, but will result in great loss of face within the cavalier community.
Finally there are some philosophical ruminations on the nature of being a cavalier. By entering the battlefield you are assenting to your own death. Your enemy today may be your ally tomorrow. Your goal is to complete the mission, not to kill your opponent. Leave grudges on the battlefield. An honorable death demands no reparations. This is the section people quote when they want to look wise and mysterious.
It should be noted that even pirate and outlaw pilots follow these rules. To follow the code is to be a cavalier. A pilot who intentionally breaks the rules is no longer a true cavalier, and as such is no longer entitled to the protections and benefits that cavaliers depend on.