Bonus feature is a term mostly used by slot machine and video slot players. It describes additional features the player can trigger during the game.
The first slot machines had no bonus features and involved only symbols, which made the whole experience relatively simple but also tedious after a while. However, as the number of slot games increased, software developers wanted to introduce more diversity in their titles, which is why they started to add intricate mechanics to their games to make things more exciting.
Today, there are dozens of different bonus features, such as free spins, sticky wilds, cascading reels, and many others. Some of the features even trigger a mini-game you get to play while playing a video slot. What’s fantastic about these bonus features is that all of them are triggered differently, making each slot unique in one way or another.