I would say that tipping at casino supervisor and management level, and host level is prohibited by most casinos because of the appearance of the player "buying" favorable consideration for his/her play. My experience at the casino supervisor/pit manager level is that we were forbidden from accepting gifts from customers. I am certain that our hosts were also prohibited from accepting gifts. Most hosts make a pretty good salary because the casino hires them to use their "book" to bring in players that spend. I know it is tough for a host to decline a gift but that host should think about what would happen if he/she falls from grace with the benevolent player. Tipping dealers and service personnel is the only accepted form of gratuity in most casinos.