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How to play doubles in ping pong
Decide who serves first.
This can be determined in many ways--you can flip a coin or you can volley. To volley is just to toss the ball and play it until someone scores if you score then it is your serve, but when you volley the ball has to be hit three times in the match before some scores.
Serve from any side of your table. Hit the ball on your side once and have the ball go over the net to hit their side.