In simple terms, a bonus round is “a game inside a game”. In different slots, it can be triggered by certain combinations of symbols or special symbols, such as scatters and wilds. A bonus round can come in the form of a free extra game, free spins, a Gamble feature, and so on. Sometimes, especially when you are playing a high volatility game, a bonus round can result in huge winning! Most new online slot games, especially video pokies, came with various bonus features.