The Tackling
Tackling is a defensive action. It consists of intercepting the player in possession of the ball and holding on to him or making him fall over (with one's arms) so that he releases the ball. Players on the ground after a tackle (the tackler and the player who was in possession) must release the ball, move away from it and may not rejoin play until they have got back to their feet. It is against the rules to throw oneself on top of a tackled player who is in possession of or near the ball.
The Kick In Open Play
Kicking enables a team to find touch, to gain ground or, of course, to score points. It is an essential part of the play. It consists of kicking the ball in the desired direction, though there are several different types of kick:
The kick ahead may be collected by the kicker to make ground, or any either player behind him et the time the ball was kicked.
The "up and under" (a kick launched high enough to enable the kicker's team-mates to position themselves to jump to collect the ball before they touch the ground).
The centralising cross-kick (a kind of up and under allowing the ball to be sent back towards the middle of the pitch).
The drop goal which is kicked on the half volley between the goalposts and over the cross bar. If successfull, this kick scores 3 points.
The Try
A player scores a try when he touches the ball down in the opponent's in-goal.
Calling For The Mark
A player may call for the mark when he catches the ball on the volley or on behind his 22 metre line. The ball must have come directly from an opposing player's kick. The player who catches the ball must call "MARK".
The Offside
A player is offside:
when he is in front of a team-mate who has the ball or has just played it.
during a ruck or scrummage, if he remains or advances in front of the offside line. Only the nulber 8 is allowed to detach himself from the ruck or scrummage and collect the loose ball.
If before a line-out is completed, a non-participating player advances or remains in front of the offside line.
Unsportsmanlike Conduct
Unsportsmanlike conduct occurs where an action breaches the rules or spirit of the game. This includes obstruction, unfair action, dangerous play, unsporting behaviour or repeated foul play. These infringements may result in players being sent off, cautioned, or the awarding of penalty tries or penalty kicks.
The Red And Yellow Cards
In the Five Nations Tournament and in all international matches, the yellow card represents a caution. Now in the Six nations Tournament, if the referee judges a player to be guilty of an aggressive play or accidental unsportsmanlike conduct, he must temporarily exclude the guilty player without further warning. To do this, he summons the player at fault, and shows him a yellow card. The player is sent behind the opposing team's dead ball line. The minimum duration of the exclusion is 10 mins.
The red card means a player is definitively sent off. It is handed out in cases of violent conduct, dangerous play and dissent or threatening behaviour towards the referee.
The Penalty
This is a punishment for a team that has committed a foul. The penalty kick may be taken in the same way as a conversion, and in this manner is worth 3 points. It may also be taken rapidly in order to keep play moving. Finally, it can be kicked into touch, and in this case, the kicking team will take the throw-in. The team awarded the penalty kick can ask the referee to replace it with a scrummage.
Source & Credit:
The Rules of Rugby