Accepted legal gaming classifications are available to state gaming boards to restrict which class of slot machines can be used in a casino or other gaming area, specifically Class I (tribal ceremonies), Class II (bingo), and Class III (for everything else, including Las Vegas style casino games).
Gaming Classifications
PS 15: Legal Gaming Classifications | Hawaii Slots 2017
Gaming classifications are defined at the federal level of government when few other terms are. Plus, Hawaii slot machine casino gambling 2017.