Indian Gaming and Regulatory Act

The Indian Gaming and Regulatory Act made gambling a multi-billion-dollar industry on Indian reservations, under the control of Indian tribes. It was enacted in 1988 in response to the U.S. Supreme Court decision of California v. Cabazon Band of Mission Indians (1987), which affirmed the sovereignty of Indian tribes over gambling and established that if a state allows any form of gambling, then it must allow Indian gambling too without regulating it.

But states do retain some regulatory authority over Indian casinos based on the state's power to grant or deny liquor licenses to them.