RTP stands for Return to Player. RTP is a percentage that shows the average amount that the game returns to winning players. You can also think of RTP as the inverse of the house edge, so the RTP plus the house edge will always equal 100%. For example, if the RTP for a given game is 95%, that means the game will return 95% of winnings to players and 5% to the house.
At MyPrize US, creators are included as part of the house when you play in their rooms.
RTP differs per game, and you can see each game's RTP by using the game's menu to navigate to the 'Info' page.