Expanding wilds is a feature commonly found in video games, particularly in the genre of slot machines. It refers to a game mechanic where certain symbols, known as wilds, can grow to cover entire reels. This increases the chances of forming winning combinations, as wilds can substitute for other symbols. When wilds expand, they often trigger additional bonuses or free spins, enhancing the overall gameplay experience. Players enjoy this feature because it adds excitement and unpredictability, making each spin potentially more rewarding. Expanding wilds can be a key element in attracting players to a game.