BUMP: A player is permitted to ride into another player so as to spoil his shot. The angle of collision must be slight, posing no serious danger to horses or riders.

CHUKKER: There are six chukkers, or periods, in a full-length outdoor game, four in arena polo. Each lasts seven minutes. There is no overtime at the end of the last chukker unless the score is tied, in which case a seventh period will be played.

GOAL: Any time the ball crosses the line between the goalposts, it is considered a goal-regardless of whether the ball was knocked by a mallet or kicked by a pony. The teams change sides after a goal is scored.

HANDICAP: Handicaps in polo range from -2 to 10 “goals,” with 10 being the best. A player who is playing above his handicap level (i.e. 3 playing as a 5) is known as a ringer and is a very valuable but short-lived commodity, as handicaps are assessed and revised twice a year.

HOOK: A player can interfere with another’s shot by putting his mallet in the way of the striker’s swing. If the player reaches across his opponent’s mount to hook, it’s called a cross-hook and considered a foul.

LINE OF THE BALL: This is the concept governing traffic on the filed: The ball creates an imaginary line as it travels, and the player or players established in this line have the right of way.

NEAR SIDE: The left-hand side of a horse.

OFF SIDE: The right-hand side of a horse.

PENALTY: When a foul is committed, the fouled team gets a free hit toward the offender’s goal. The type of penalty shot awarded depends on the severity of the foul.

RIDE-OFF: This is when one player makes contact with another and attempts to push him off the line of the ball to prevent his hitting the ball.

SAFETY: (Penalty 6) When a defending player hits the ball across his own back=line, the other team is awarded a free hit 60 yards from the backline.

SIDEBOARDS: These 9- to 11-inch boards along the sides of the field are optional; they contain the ball to an extent. A player can cross the boards and remain in play, but if the ball hops over them, it’s out of bounds.

THIRD MAN: If and when the umpires disagree on a call, they refer to the “third man,” or referee sitting on the sidelines.

THROW-IN: A chukker begins (and sometimes play resumes) with the umpire bowling the ball between the two teams.

TIME-OUT: An umpire calls a time-out when a foul is committed, when an accident occurs or at his own discretion. A player may only call a time-out if his tack is broken or he is injured. No time-out is allowed for changing mounts or replacing broken mallets during a chukker, although the player may do so whenever necessary.

UMPIRES: Two mounted umpires control the game, enforce the rules and guard the safety of players and ponies.