The 'ultimate grand prize' in a slot, offering a payout on a different level from regular wins.

A feature that acts like a joker in poker, substituting for other regular symbols to complete winning combinations.

A 'key' symbol that triggers core bonuses like free spins by appearing scattered anywhere, regardless of paylines.

A core bonus round where you can spin the reels for free without using your balance, often with powerful extra features activated.

A 'game within a game' that takes place on a separate UI, such as 'Pick and Win', instead of on the spinning reels.

Any feature that expands the value of a single bet by changing the number, cost, or nature of a spin.

Any mechanism where the reel's form or symbol composition changes further even after the spin has stopped.

All the rules that define wins in new and diverse ways, going beyond traditional paylines.

Any symbol that has a unique 'ability' to drive the flow of the game and create dramatic events.

Any optional feature that allows the player to pay an extra cost to directly intervene in the game's rules or probabilities.