The Rules of Tetherball
A game is won when one player has wrapped the rope as far as it can go in her own direction.
Serve: In tetherball, possession is everything. Once a good player gets control of the ball, their opponent is in trouble. The server is required to wait until either the opponent strikes the ball or the ball has wrapped four times before they (server) can strike the ball again.
Direction: Given the disadvantage of serving, the server may choose which direction to hit for each game they serve. For each new game that they begins, they may choose either direction.
Unintentional Violations:
Stepping over the line.
Touching the rope.
Carrying or throwing. Serves must be hit, not thrown. When hitting a ball back against the direction from which it comes, the ball should bounce off the hands immediately, with no lingering contact. When hitting a ball that has passed the opponent and continuing it around the pole, the ball still cannot be carried or thrown. Thus, a less distinctive impact is to be expected.
Double hitting may or may not be intentional, but we give the benefit of the doubt. A player can hit the ball only once per wrap around the pole, except if the ball hits the pole between hits. They could conceivably "dribble" the ball against the pole, but this would be of little advantage, because they would not gain any wraps, and their opponent would likely get an opportunity to steal the ball.
When one player commits any one of these violations, the ball is stopped. The other player gets to serve, then either player can hit the ball from that point on.