Federal jurisdiction versus state jurisdiction tends to be a purely academic distinction to most attorneys and never a concern for the majority of Americans. While the first year of law school spends a substantial amount of time on concepts like the Erie Doctrine, the truth is, the application is very narrow.
However, that doesn’t mean that the use of the federal courts are not more readily available than people realize. Generally speaking, you can file a lawsuit in federal court if the basis of the suit is a federal law, or the federal government has carved out that specific area of the law as being exclusively in front of a federal court.
However, there are occasions when you can get to federal court without having any sort of federal question or law. Through diversity jurisdiction you can opt to have your case heard in federal court instead of state court.
What is diversity jurisdiction? It is when no plaintiff and defendant reside in the same state and the controversy exceeds $75,000.
But why might one choose to go to federal court, which tends to be more finicky regarding the rules of court and rules of procedure? Well, for one, the very basis of why there is a carve out for diversity jurisdiction is because the federal government wanted to ensure that there are not only fair trials, but the appearance of fair trials, and so if you are not from a particular state, maybe you assume the judge/jury won’t give you a fair shake.
Another reason might be expediency of a trial. Especially after the financial meltdown of 2008 courts all across the state of California began to close down and consolidate. This meant that each courthouse became inundated with more cases then they could handle. As a result, in almost every courthouse now has at least an 18 month delay between filing to trial (which is much better than what it was at its worst). However, federal courts tend to have a shorter turnaround period.
Keep in mind that federal courthouses have their own rules of civil procedure and so they will not apply the state rules (Erie Doctrine situations exempted), but they still apply state law. So, if you are trying to go to federal court for more favorable laws, you will be out of luck.