The answer to this one is quite easy. The games with high RTP (Return to Player) have better odds of paying out. You are better off playing an online slot that returns 98% of all money wagered in the long run than a game with an average payout rate of 87%, for instance. Many accredited casinos are happy to share their slots' return percentage with players. This enables you to draw comparisons and pick the titles offering you the biggest long-term returns.