In online and video slot games, a wild symbol is a special icon that can substitute for other symbols to help create winning combinations. This means that if you have a wild symbol on the reels, it can replace any standard symbol, increasing your chances of winning. Some wild symbols also come with additional features, such as multipliers or expanding effects, which can enhance gameplay. For example, an expanding wild symbol may cover an entire reel, further boosting the potential for big wins. Overall, wild symbols add excitement and variety to slot games.