A "bonus game" is a special in-game feature offered in many online slots. It's an additional game that can be activated as part of the regular game. Certain symbol combinations often have to pop up in order for a bonus game to start. These bonus games often offer special winning opportunities and can bring players additional rewards such as free spins, extra coins or even progressive jackpots. A bonus game is a great way to increase the level of fun and your chances of winning.