There are several basic rules to keep in mind while playing polo. One of the most important is called the line of the ball, which means that a right of way is established when the path of the ball is to the right of the player. The last individual to strike the ball has the right of way, and no one may cross the player to take over this position. However, another player may go to the side of the person with right of way to hook or block, as long as he or she is not impeding the other player.
Blocking involves keeping the other player from hitting the ball, while hooking involves actually having contact with another player's mallet with one's own mallet. An interesting fact is that players only may hold the mallet in their right hand, since it is thought that left-handed players do not hit with as much accuracy.