Indian gaming, also called Native American casino gaming or tribal gaming, is tribal government gaming. It is government gaming built on sovereignty and consequently is a corollary to state gambling such as lotteries rather than a corollary to corporate gaming. While the types of games offered in casinos might differ in format from ancestral indigenous games, gaming itself is a cultural tradition in many tribes, including those who operate casino gambling. Native American casino gaming is a $33.7 billion industry operated by nearly 250 distinct tribes in twenty-nine states in the United States. The Indian Gaming Regulatory Act (IGRA) of 1988 provides the framework for tribal gaming and the most important case law in Indian gaming remains Seminole Tribe of Florida v. Butterworth, in the US Fifth Circuit Court of Appeals, and the US Supreme Court decision over California v. Cabazon Band of Mission Indians.