When someone asks "Are random number generator real?", the figure quoted most often is return to player, and read alone it tells a player very little. It describes how much a game pays back across millions of rounds: a slot listed at 96 percent keeps four of every hundred units staked over that span. It says nothing about a single evening of play.
Progressive jackpots lower the return an ordinary player experiences. A part of every stake funds a prize that very few players will ever win, so the everyday return sits below the published figure even when that figure is accurate. Betting systems do not change this arithmetic. Changing stake sizes alters how fast a balance moves and how wide the swings become, while the edge built into the game stays where it was set.
Reputable studios publish the return range of each title and send their random number generators to an independent test lab. The certificate names the game, the version tested and the date of the test. A licence usually obliges the operator to offer certified games only, which is a real constraint on what can be installed. The same licence rarely requires the figure to appear on the game screen, so the certificate and the help panel remain the places to confirm it.
Many slots are released in several return versions, and the operator chooses which one to install. The difference between the highest and the lowest version can reach several percentage points on the same title, with identical graphics and rules. Nothing on the reels shows which version is running. The game's own help panel states the figure for the copy in front of the player, and it is the only reliable place to read it before staking.
Some studios rate volatility on a scale inside the game's information panel; reviews that estimate it from a short test rely on far too few spins to judge.
In the game's information panel, which describes how the bonus rounds and features work next to the return figure for that particular copy.
Part of every stake funds a prize very few players ever win, so the everyday return an ordinary player sees sits below the published figure even when that figure is accurate.
Where available, the history lists recent rounds with their stakes and results, useful for checking a session; a handful of rounds proves nothing about the long term payback.