RTP (Return to Player) is a percentage that represents the theoretical amount a game pays back to players over a very large number of spins or hands — it is a long-run statistical average, not a guarantee for any single session.
For example, a slot with 96% RTP is mathematically expected to pay back $96 for every $100 wagered over millions of spins. The remaining 4% is the house edge.
RTP is calculated by the game provider (Pragmatic Play, NetEnt, Evolution and others) and is usually published in the game’s information/help screen. It doesn’t change based on time of day, how long you’ve played, or which operator hosts the game — RTP is a property of the specific game itself.
When comparing similar games, a higher published RTP is generally better for the player over the long run, though short-term results can vary widely due to variance.