How Outcomes Are Calculated. When a spin occurs, the combination of symbols that show up on the reels determines the payout; different combinations resulrummy 2023t in different rewards. The payout percentage, also known as Return to Player (RTP), shows how much a player can anticipate winning back on average over time. An RTP of 95 percent, for example, means that a slot machine should theoretically pay out $95 for every $100 wagered. The function of volatility.