ANSWER
Every show has it's own set of rules - guidelines that define the show. Here are the Laws of Lexx, borrowed from a BillBored post:
1. There shall be no rubber-faced aliens.
2. All creatures possess a sense of humour.
3. There is no Prime Directive.
4. There are no life forms more intelligent than humans, unless and until such a life form does the requisite script writing.
5. All planets worth landing-on have human (or reasonably close) life forms.
6. All humans (or reasonable facsimiles) speak the same language.
7. Humans must physically travel to other locations. There shall be no time travel because it has been done before, and done before, and done before, and done before...
8. Technology will rarely work as advertised.
9. No one shall ever defeat an enemy because they are good shots and the enemy are bad shots.
10. Stanley Tweedle shall never lose his hat.
WHO GOT IT RIGHT: Andie J.