WMS Gaming Inc. manufactures slot machines. It serves casinos worldwide. WMS Gaming Inc. was formerly known as Williams Gaming, Inc. and changed its. Advanced Drainage Systems Inc. stock price, stock quotes and financial overviews from MarketWatch. WMS Gaming is a manufacturer of slot machines, video lottery terminals and software to help WMS shareholders received $ per share. At the time of the merger, the company's stock ceased trading on the New York Stock Exchange.