They first showed up in Kentucky in 2021. Called gray games, they looked and acted like a slot machines, but the companies that manufactured the machines made the spurious claim that they were legal because they were actually games of skill. Before long, the machines grew to be so popular that, by some estimates, there were more than 5,000 of them, taking up residence in bars, restaurants and convenience stores across the state. "They spread like rabbits," said Majority Floor Leader Senator Damon Thayer of the games that got their...