How many balls are there in a standard pool game?

depends on the game, most common are 8-ball in which there are 15.one player plays1-7, the other plays 9-15,then the 8. the other is 9-ball in which there 9. In 9 ball pool you hit the nine ball in last.
10 or 16. The three most common pool games are 8 Ball, 9 Ball and Straight Pool. Both 8 Ball and Straight Pool use 15 numbered balls and the cue ball. In 9 Ball, only the first 9 numbered balls are used plus the cue ball.