Payout percentage refers to the percentage of the total amount of money that a slot machine would take from players over a period of time, and then pay out as a win to a player. The percentage usually ranges from 75% to around 98%. This percentage varies depending on the slot machine and the casino. The RTP (Return To Player) percentage is a measure of the percentage of bets a game pays out to players (usually over at least a million games) and is a generally accepted guide to how a game will perform. If you are in any doubt about this, contact customer support.