Russian President Vladimir Putin has signed a law setting up a gambling zone in Crimea, the territory Russia annexed from Ukraine in March.
Four official gambling zones were created in Russia five years ago when the authorities acted to curb betting.
Russian MPs argue that the new law will attract investment and boost visitor numbers in Crimea, with its network of Black Sea holiday resorts.
Western states refuse to recognize Crimea's unification with Russia.
While the annexation, which followed a referendum on self-determination, was virtually bloodless, it encouraged pro-Russian separatists in eastern Ukraine to take up arms against the new authorities in Kiev.
There were concerns that Crimea's tourist revenue would fall sharply this summer as a result of the crisis.
Russia has sought to maintain summer visitor numbers with holiday promotions while state companies have been encouraged to treat their workers to holidays on the peninsula. Initiatives include visa-free travel to Crimea for Chinese tourists.
The new law also extends the gambling zone in Russia's southern Krasnodar territory to cover the city of Sochi with its Winter Olympics venues. Casinos are expected to be built near the Olympic Village, Russian media report.
The other three gambling zones were set up in Russia's Baltic enclave of Kaliningrad, the Far East and Siberia's Altai territory.