A high roller is a player who regularly stakes large amounts on each bet, far above what most players wager. Casinos give them high-limit tables, private salons and VIP live dealer rooms, because standard limits are too low to keep their interest. For them, bigger risk is part of the appeal.
In return for that volume, high rollers are usually offered perks: a personal host, RFB comps, junket trips and, at land-based venues, approved credit lines. How much they get depends on their relationship with the casino. The biggest spenders are often called whales, and the opposite profile is the low roller. Online operators usually spot high rollers from deposit and turnover data and move them into a dedicated VIP tier with their own limits and bonus terms.