Authorities charged 28 people after seizing at least 100 illegal gambling machines from 48 locations in Gaston County on Thursday.
Suspects were charged with the misdemeanor offense of possessing a slot machine. Police said more charges are expected.
The seizures and arrests followed a several-month investigation called Operation Pot of Gold, Gaston County Police said.
Police gave anyone they found playing the machines the phone number of the North Carolina Problem Gambling Helpline, 877-718-5543.
The machines will be held as evidence until a court order is issued to destroy them. Any money seized will eventually go to the Gaston County Schools, police said.
Assisting Gaston County Police were officers from the Gastonia, Mount Holly, Cherryville, Belmont and Bessemer City police departments and N.C. Alcohol Law Enforcement.