Wild symbols are symbols which can create a winning combination on the reels combined with any other symbol. There are also wild symbols which can reward you with a big amount of coins if you get the right number of them in a winning combination, since in some slot machines this symbols has the highest pay-out value of all symbols. If you would like to know how much this pay-out value is then you should click on the paytable button in the game you are playing, where this information should be stated.
The wild symbols appear randomly on the reels and sometimes only on specific reels in the game. Usually the Wild symbol substitutes for all other symbols except for scatter symbols, free spins symbols and bonus symbols.
There are different types of wild symbols such as expanding wilds which expands all over the reels, and transform every symbol on that reel into a wild symbol. Sticky wild symbols are wild symbols which stay in one place on the reels whilst the other reels continue to spinning, which gives you a higher chance of getting a winning combination. Shifting Wilds are wild symbols which moved horizontally across the reels instead of staying in once place as with the sticky wild. Stacked Wild symbols are symbols which are stacked on top of each other on one reel.
As you can see Wild symbols comes in many different versions, and they are a great addition to the slot games, making it more exciting for players.