Megaways is a slot payout structure that changes the number of symbols on each reel every spin, creating up to 117,649 ways to win — far more than a classic slot's fixed paylines.
In a Megaways game, the reel layout and number of winning combinations vary from spin to spin, since the screen layout itself changes dynamically. A classic slot, by comparison, uses a fixed number of paylines that stay the same every round.