The object of the game is to be the first player/team to reduce the score from 301 points down to zero. You will take turns throwing darts to hit different targets on the dartboard (3 darts per turn). Different areas on the board are worth different points. The scored points will then be subtracted from the total 301 points or your remaining points at the beginning of each turn.
To win the game, you have to bring the points down to precisely 0 by hitting a double section again. This is called “doubling out.”
For more information: https://dartsgamecenter.com/how-to-play-301-darts