Each level in Fishing Duels requires a certain number of fish to be collected in order to win the game. The player who first collects the required number of fish is the winner. To collect fish, a player must make a match of them in a row or column of 3 fish or more. Diagonal matches don't count. To move a fish and perform a match, there are two ways: a) click on each of the adjacent cells to switch their positions b) click and drag a cell towards the position of the other cell with which you want to switch places.
Either of the above actions will create a chain of 3 or more fish in a row or column, removing them from the board and making all the items above them occupy their cells. If any of the cells containing the matched candies, had fish in them, the action will cause the fish to be removed. When collecting fish, you may watch their number increasing on the top of the board, next to your avatar.