Inspired by Rod Serling's celebratory trip to Las Vegas when The Twilight Zone (1959) was first signed. His wife Carol Serling had good luck at the casino, but he himself kept losing to a slot-machine not unlike the one shown here, and battled it for a good while.
Even though the episode takes place in Las Vegas, it was filmed in California where slots were illegal at the time. The producers had to broker an arrangement with the LAPD to borrow real slot machines that had been confiscated by the police for use in the episode. Said producer Buck Houghton, "There was a policeman on the set at all times, to make damn sure that somebody didn't take one off and set it up in his uncle's barber shop."
The name of the hotel Franklin and Flora are staying at is never given, but the casino is called Oasis, putting them at The Dunes, which operated from 1955 until its closure and subsequent demolition in 1993.
The slot machine Franklin uses is the same prop that Ace Larson has in his coffee shop in The Prime Mover (1961).
The slot machine shown chasing Franklin at the end of the episode, is modified with a flashing lower light where the coin slot used to be.