RTP and volatility are properties of a game's mathematical model, and they are routinely read as a promise about outcomes. Both describe how payouts are distributed over a long run of play, and neither predicts the result of a single session.
What RTP means
Return to player is the share of stakes returned to players as winnings, calculated from the model across a very large number of rounds. It is a property of the game, not a reading for a given day or a given account: the spread of the actual result around the theoretical figure narrows as the number of rounds played grows. The complementary quantity is the advantage built into the maths, set by the design of the game rather than by any setting on the operator's side.
One detail carries commercial weight: the same title can ship in several RTP configurations, and choosing a version is a configuration decision, constrained in a number of jurisdictions by regulatory requirements.
What volatility means
Volatility describes the shape of the distribution — how rarely and how large payouts occur at one and the same RTP. Low volatility means frequent small wins; high volatility means long empty stretches and rare large events. Two games with identical RTP can deliver a fundamentally different experience and burn through a balance at a different pace.
Why both have to be read together
Taken separately, neither number describes the game. RTP sets the long-run economics, volatility sets the dispersion around it — which is what a player actually feels. For portfolio work the combination is what counts: a lobby assembled purely from high-volatility releases behaves nothing like a balanced one.
The correct reading is straightforward: both figures characterise a distribution, not a forecast. Using them as an argument in promotional communication is improper; using them as an input to product planning is exactly what they are for.