. . .which is another word for regulation.
All institutional legal power rests with the state, though with the states' ratification of the Constitution of the United States, some powers have been delegated to the Federal government.
Counties, cities, towns and special bodies such as fire and school districts are granted limited regulatory power by the state. The codes, ordinances, regulations etc can be vacated by the state (which is what we want to happen in this case), and DO NOT have the power of law in and of themselves. Violation of these can result in a stay in city or county jail, but not a prison sentence.
When I use the word "law," I mean a statute (which may be either a felony or a misdemeanor) rather than an ordinance, code, regulation, etc. (which may be a misdemeanor or an infraction). You are using the word to include regulations, codes, etc, which is not quite accurate. A cop from anywhere in Nevada has the authority to enforce a Nevada statute anywhere in the state. A cop from Reno does not have the authority to enforce Las Vegas city codes unless a specific enabling regulation exists between the two cities. He also can't enforce Reno codes anywhere outside of Reno, and can't make an arrest on an in-town violation of those codes outside of Reno (that's why they get a local cop to go with them if they are making such an arrest). City courts may not try statue violations, and technically neither can county courts -- a Superior Court is "in and for" the county which it serves, and Superior Court judges are elected within that county, but their authority is actually delegated by the state.
One example of the difference between law and regulation is DUI. There is a state law making DUI a criminal offense, punishable by a term in prison, IN ADDITION to the vehicle code REGULATION against DUI, which specifies administrative punishment (points put on your driving record).
