Return to Player is the percentage of total staked money a game is designed to pay back to players over an extremely large number of plays. Expressed as a theoretical long-run figure, it describes statistical expectation across millions of rounds rather than any guarantee about an individual session or a single player's outcome.
The house edge is the built-in mathematical advantage an operator holds on a given game, expressed as the percentage of each stake it expects to retain over the long run. It is the complement of Return to Player and determines the average theoretical cost of play across many rounds rather than any single result.
Volatility describes how much a game's results swing around its long-run average. High-volatility games pay larger prizes less frequently, producing wide bankroll swings, while low-volatility games pay smaller amounts more often. It reflects the distribution and timing of outcomes, not the overall percentage a game returns to players.
A Random Number Generator is the software component that produces the unpredictable numerical outcomes behind digital casino games, such as reel positions or card draws. It is designed so that each result is statistically independent of previous ones, giving fair and non-sequential outcomes that cannot be predicted or influenced by the player.
A payline is a defined pattern of positions across a slot's reels along which matching symbols must land to form a winning combination. Lines may run straight, diagonally or in zig-zag shapes. The number and layout of paylines determine which symbol arrangements qualify for a payout on any given spin.
A wild symbol is a special slot symbol that substitutes for other standard symbols to help complete winning combinations. It typically cannot replace special symbols such as scatters or bonus icons. Wilds may be ordinary, expanding, sticky or stacked, and are a core mechanic for increasing the frequency and size of wins.
A scatter symbol is a special slot symbol that pays or triggers features based on how many appear anywhere on the reels, rather than on a specific payline. Scatters commonly unlock free spins or bonus rounds and often award a payout regardless of position, making them distinct from standard line symbols.
Free spins allow a player to spin a slot's reels without deducting their own balance, while still being eligible for winnings. They may be triggered inside a game as a bonus feature or granted by an operator as a promotion. Promotional free spins typically carry wagering requirements and other conditions before winnings can be withdrawn.
A progressive jackpot is a prize that grows over time as a small portion of each qualifying bet is added to a shared pool, until one player wins it and the pool resets. Progressives may be confined to a single game or linked across many games and operators, allowing the top prize to reach very large sums.
A wagering requirement is a condition attached to a bonus that specifies how many times the bonus amount, or bonus plus deposit, must be staked before related winnings can be withdrawn. Usually expressed as a multiplier such as 30x, it governs when bonus funds convert into withdrawable cash and which games count towards it.