Take the normal laws you know and apply these additions and changes:

-Humans and other creatures from other cities must meet with the city's elected official to gain entrance

-Any non-vampire entering the city is doing so at their own personal risk

-It is against the law to harm any non-vampire that has entered the city legally

-Any actions taken against an illegal entrant to the city will be upheld as self-defense, and the vampire in question will not be held responsible for any sustaining injuries or deaths inflicted upon the illegal entrant.