https://www.liveabout.com/tipping-guide-for-slot-players-536668#
But, if that is in the common casino where tipping is not necessarily determined, it may depend on yourself whether you are going to give any tup or not when you are winning. Some people may think that giving tips after winning becomes one of the things they only give gifts to the casino workers. But if you don't win any slot or whatever in the casino, moreover you are lost, I don't think that it is not necessarily tipping them. I am sure that the casino workers understand this. But if you are winning moreover winning the jackpot and you don't give them tip, this may make them hate you inside, although they are not showing really on their face.