For scoring four or more tries in a match, a try bonus point is granted. If a side scores four tries in a game and loses by seven points or less, they receive both bonus points. If they score four tries and lose by more than 7 points, they only receive one bonus point.
The bonus point system was introduced in 1999, and since then it has been awarded after every Four Nations tournament played by Australia, New Zealand and England and after each World Cup year (except 1990). It can also be awarded by the IRB if there are three or more consecutive years when three or more tournaments are held within those years.
A player must touch the ball down in possession of his team in order for a try to be scored. A player cannot score a try unless he is in contact with the ground below a high backline position. The exception to this rule is if the player is deemed to have been held up above this height (for example, if a defender pulls him down). In this case, the player will be allowed to score a try.
There have been several attempts to change this law over the years, most notably by former Australian captain Steve Walters in 1997.
After scoring a try (including a penalty try), a team is granted a "conversion" kick at goal. A successful kick earns you two points. The kick is taken from a location parallel to where the ball was grounded for the try, which can be as close or as far away from the goal line as the kicker chooses.
An attempt on goal from outside the 22-yard line results in a "free-kick", since there is no try score to convert. The free-kick can either be taken directly, or played by passing it forward. If the player takes the free-kick himself, a free-kick is called either way. If it's passed, then the player with the ball must take a subsequent free-kick.
A player is eligible to take a conversion if he scores a try or gets into the box through a free-kick. The player does not have to touch the ball to be credited with the try.
If a player knocks on with the ball inside his own half, a free-kick is given at the place where the ball went down.
Players are not allowed to use their hands when taking a free-kick, nor can they step out of the penalty area. If a player does so, the referee will call "offside".
Difference in Points scored by two different teams in a single match. If one team scores more points than the other, then they win the match.
PD means that the game is drawn. This happens when each team earns exactly the same number of points - 3 in this case. To determine the winner, a re-play of the match is usually held. If the same result occurs then the referee raises his flag to indicate that the match is a draw.
In rugby, a draw is called a "tie".
There are several ways in which matches can be tied. A tie can occur if there is a repeat scoring event (i.e.: both teams score a field goal or penalty kick after overtimes have been played) or if the match ends in a no-score draw. In the last case, the match typically will be replayed within a certain time limit (usually 7 days).
A match that is not tied at the end of normal playing time wins automatically for the higher-ranked team.