RTP is an acronym for Return to Player, and is also known as payout ratio or payout percentage. It is a term used in new casinos online and traditional casinos to describe the percentage or sum of all the wagered money a slot machine or VLT (Video Lottery Terminal) will pay back to players over time.

If a game has an RTP or payout percentage of, for instance, 98%, then the casino will pay out $98 for every $100 wagered on average. There's a possibility that the RTP for a game can change with time due to software updates and updates that the developer makes to the game.