You can wear anything you want at Casino Royale. I have seen over the years, anything from shorts and tees, to suits. They will be more than happy to take your money no matter what you are wearing!!!! All I bring to the island for years is a pair of Tevas.......and have never worn a pair of long pants anywhere on the island. This has been going on now for almost twenty five years. enjoy, relax, and good luck at the casino.