I'd like to start an online FPS tournament game where all players wager a small amount of money before each round and the winners take a certain percentage of the funds .
Depending on their skills and positions at the end of each round(1st,second,...),
the amount varies.
Native American Law Attorney
Recent legislation has made online gaming legal depending on your state. Also depending on the structure you may be able to legally conduct your tournament. This is a highly regulated area of the law and you must consult with a qualified attorney to ensure compliance with the law.
This is not intended as legal advice. It is only provided for educational purposes and cannot be relied upon as legal advice. Further no attorney client relationship is or has been formed by answering this question.