With 15 players per side, a rugby team is divided into forwards and backs. Forwards are usually the larger, stronger players on the team. Their main job is to win possession of the ball. The backs are often smaller, faster, and more agile and typically exploit the ball possessions, which are won by the forwards.

Both the forwards and backs play at the same time. All 15 players assemble on the field, called a pitch, and the match starts with a kickoff. The receiving team generally tries to move the ball downfield to score. However, in attempting to score, the team cannot pass the ball forward. The defenders can only tackle the ball carrier.

After the ball carrier is tackled, there is a scramble for the ball. Hence, a tackle does not stop play in rugby. Once tackled, the player must release the ball immediately so play may continue. The tackled ball carrier should attempt to release the ball advantageously toward his or her team. Still alive, any player may pick up the ball.

When players from both sides fight for the ball when it is on the ground, the situation is known as a "ruck." This can be described as the most dynamic action of the game. The team that retains ball possession during tackles and ensuing rucks has an advantage over the other team.

Sometimes the ball is buried during a tackle, or a player commits a minor infraction of the laws (a penalty). If the team that has not offended doesn't first gain an advantage from the continuance of play, the referee will stop play and call for a scrum to restart the match. The non-offending team has the advantage of putting the ball into the scrum and, therefore, will most often win possession.

During a scrum the ball must be worked backwards, and the player's hand cannot touch the ball in the scrum. When the ball emerges, open play resumes. The remaining players who are not involved in the scrum must stay behind their respective offside line.

Once a team has worked the ball downfield and crossed the opposing team's goal line, and forced the ball onto the ground with downward pressure, a try is scored. Each try is worth five points. After each try, the scoring team has the opportunity to score two more points with a conversion.

Both teams' play to score tries during two 40-minute halves.

The Pitch

The field that rugby is played on is called a pitch. The pitch is expected to be 100 metres long by 69 metres wide. The sidelines are called touchlines and there are two in-goal areas, which are expected to be 10 to 22 metres deep with a tryline marking the front and a dead ball line at the back. The goal posts are located on the try line and are 5.6 metres apart with a crossbar set at 3 metres. The height of the posts varies according to the club's wishes.

Other important lines on the pitch include the half way mark at 50 metres. A dashed 10 metre line set each side of the 50 metre line, which is used to judge kickoffs, and a solid 22 metre line marked 22 metres from each tryline. Other lines include two dashed lines set at 5 and 15 metres marked parallel to each touchline. These lines are used mostly to identify the zones for lineouts.

Rugby union is played in different variations depending on the number of players on the field for each team. The typical game is played with fifteen players per side and lasts 80 minutes, with 40 minutes being played in each half. An abridged version is also very popular but is played with seven players per team over two seven minute halves. A less often played version is called tens and is played with ten players per side.

The Players

Teams in a fifteens match will consist of two groups of players, the forwards and the backs. Each position has a specific number and responsibilities during the two 40 minutes halves of a match. The players are as follows:

Forwards - the group of players normally numbered 1 through 8 who bind together into scrums, lineup for lineouts, and commit themselves to most rucks and mauls.

#1 Prop - (loosehead) Responsibilities are to support the hooker during scrums and 2nd rows during lineouts.

#2 Hooker - the frontrow forward wearing No. 2. The player is supported on either side in the scrum by props and is required to gain possession of the ball in the scrum by hooking or blocking the ball with one of his/her feet. The hooker will normally also be the forward throwing the ball into the lineout.

#3 Prop - (tighthead) Responsibilities are to support the hooker during scrums and 2nd rows during lineouts.

#4 & #5 - Lock - either of the two forwards normally wearing No. 4 and No. 5. Typically the largest players on the field, they have primary responsibility for being the power in scrums and securing the ball in lineouts. Due to their size, they are also normally powerful forces in all loose play, rucks, and mauls. Also known as Second Row.

#6 & #7 - Flanker - either of the two forwards wearing No. 6 or No. 7. Also called wing forwards or breakaways they bind to the scrum outside of the locks just behind the outside hip of the props. They can play always on the same side of the scrum or can specialize on either the weakside or strongside. The players with the fewest set responsibilities, their job is to aggressively pursue the ball, gain possession, and take off running. Also known as Breakaway Forward.

#8 Number 8 - the forward who wears the jersey with the No. 8. This player binds into the scrum normally at the very base between the two locks. His/her responsibility is to initiate attacks by the forwards from scrums or to provide a stable ball from the scrum for the scrumhalf. Backs - the group of players normally numbered 9 through 15 who do not participate in scrums and lineouts, except for the scrumhalf.

#9 Scrumhalf - the back wearing No. 9 who normally feeds the ball into a scrum and retrieves the ball at the base of scrums, rucks, and mauls. Can also be called the halfback.

#10 Flyhalf - the back wearing No. 10 who normally receives the ball from the scrumhalf. Also called the Outhalf, Outside half or 1st 5/8th, he/she will call plays for the backline, pass the ball to other backs, or provide most of the tactical kicks. Also known as First 5/8th.

#11 & #14 - Wing - either of the two backs wearing No. 11 or No. 14. Each will normally stay on the same side of the back line they are on throughout the match and are typically expected to be the fastest sprinters in the side. Wingers also have key duties during defense helping the fullback cover kicks and counterattacking.

#12 & #13 - Centre - either of the backs wearing No. 12 (inside) or No. 13 (outside). Powerful runners who are the heart of the back running attack and defense. The inside centre can also be called the 2nd 5/8th.

#15 Fullback - the back wearing No. 15 who normally plays deep behind the backline. In offense the fullback is a dangerous attacking position hitting holes unexpectedly at pace, in defense the fullback has primary responsibility for covering all tactical kicks down field by the opposition.

The Terminology of Rugby

Advantage Law - Allows play to proceed after an infringement in the case of the non-offending team receiving an advantage.

Attacking Team - The team in possession of the ball.

Backs - Players who spread out and attempt to run the ball delivered from a scrum or lineout.

Dead Ball Line - The limit to which a try can be scored beyond the goal line.

Defending Team - The team not in possession of the ball.

Drop Kick - A kick made after the ball has reached or bounced off the ground. Worth three points if it clears the goalposts; also used to restart play after a score or certain other occasions.

Forward Pass - A violation that usually results in a scrum to the non-offending side.

Forwards - Players who pack in a scrum or throw and jump in a lineout.

Free Kick - A relatively minor law violation that allows the non-offending side to restart play in an unopposed fashion. Opponents must retreat 10-meters and wait for the non-offending team to kick the ball through the mark. A free kick cannot be taken for goal.

Infringement - A breaking of a law.

Intercept - To catch a pass intended for a member of the opposition.

Knock On - The accidental hitting of the ball from the hands or arms toward the dead ball line. Results in the same scenario as a forward pass -- a scrum to the non- offending team.

Lineout - Restarts play after the ball goes out over the touchline. The team that didn't touch the ball last has the throw-in.

Mark - The place where the referee signals play will be restarted. For example, the referee marks where the scrum will take place, or where the penalty has occurred.

Offside - Players in front of a member of their own team who was last in possession of the ball, or in front of established lines at a scrum. Lineouts of loose play are said to be offsides. In some instances, one can retreat to an onside position without penalty; other times the infraction is automatically a violation.

Pack - Forward unit of a team, engages in scrum and lineouts.

Penalty - Awarded after a serious infringement of the laws. Offenders are required to retire 10-meters while the opposition is given possession to restart play unopposed. Many times the non-offending team will attempt a kick at goal, worth three points.

Put In - Rolling the ball down the center of the scrum tunnel.

Ruck - A ball-winning activity following a tackle and release; a ruck is formed if a player from both teams is in physical contact over the ball.

Scrum - A way to restart play where a bound group of players form a tunnel with the opposition.

Sevens - An abbreviated game of rugby that follows the same laws but for the number of players and time of the contest. A 7s team fields only seven players; each half is seven minutes long. Much like a game of three-on-three full court basketball, it's a wide-open contest.

Set piece - A term for scrums and lineouts.

Support Players - Players who position themselves to increase the ball transfer options of the ball carrier.

Tap Kick (or "tap move") - A gentle kick to oneself, followed by a pick up, used to restart play after either a penalty or free kick is awarded.

Throw In - Throwing the ball down the middle of a lineout.

Touchline - The side boundary of the field (sideline).

Try - Forcing the ball onto the ground with downward pressure over the opposition's goal line.

22-meter Line - Balls kicked out of bounds from behind the "22" restarted by a lineout where the ball went out; balls kicked out of bounds from in front of the 22 are restarted by a lineout where the ball was kicked. The exception is a ball kicked out of bounds immediately after a penalty has been awarded; the lineout is held where the ball went out and the non-offending team retains the throw-in.