Darts Boards are classically represented in various forms of media such as books, plays, videos/movies, etc even though they are rarely used in real life. Bust basically the object is to throw one of the pointy darts to certain areas in the board to achieve a certain amount of points. There are a lot of different ways to play and a lot of different rules that change up game play but the basic idea is the closer to the center you are, the more points you get.
If you have a dream in which you are playing darts this can have a pretty straight-forward interpretation. Basically if you have a dream in which you are playing darts then this means that you are aiming for something big in your life. You are shooting for some goal that you really want to reach. If you dream that you hit way off the dart board or nowhere near the middle then this dream tells you that whatever it is that you are so interested in getting into, you probably shouldn't because it will end in failure. If you dream that you hit the bullseye dead on then what this means is that you need to aim for these dreams because you will achieve success if you keep going for it. This is what the dart board dream was trying to tell you.
You have a certain goal you are trying to reach in life but the only way to make it there is to shoot straight and with strong purpose. The main point of this dream is that you need to make sure not to get sidetracked or else you will find yourself in deep trouble.