In the glittering oasis of Las Vegas and beyond, a subtle but significant transformation has been taking place over the past several years. The traditional bread and butter of casino resorts—the gambling floor—is increasingly competing for customer dollars with the very amenities originally designed...

The plush carpet, a dizzying swirl of crimson and gold, muffled the clatter of chips and the incessant whir of slot machines. Arthur, a man whose tie strained against his burgeoning midsection, surveyed the casino floor like a general assessing a battlefield. He’d arrived with a crisp wad of hundred...