(Note from Sean ... bumped to the front page.)
First up, I just wanted to say a big thanks to all of you who read my orginal post. Thanks for the kind words and inquisitive comments. One of the more common requests was an explaination of the rules. As you may expect, explaining the rules of any sport is quite complicated and lengthy, so bear with me, and I'll try to make it as simplified and brief as possible.
Remarkably similar to an NFL field. It's rectangular and 120m (about 130 yds) long, 100m (about 110yds) worth of playing field, with2 In-goal areas (eg. endzones) which are about 10m long . The field is around 60m wide (about 70yds), depending on the stadium. It is marked very similarly to an NFL field, with 10m increments. In the middle of each goal-line (eg. line on an endzone) is a set of goal posts, H-shaped, for kicking goals through. They however are not bent forward at the end of the endzone but right at the start of the goal-line and straight. The fields boundaries are what is known as the touch-lines (sidelines) and the dead ball line (the end of the in-goal area).
A team is made up of 17 players, 13 of which can be on the field at one time. These 13 are known as the starters, while the other 4 act as interchange players who replace players throughout the game for injury or stamina issues. The 13 players are separated in different positions with 3 distinctive groups- backs (quick, attacking players), halves (organising players) and forwards (big, defensive players). I may do another post outlining the positions in more detail later.
The main objective of Rugby League is very similar to American Football. You must protect your end of the field, and try to infiltrate their end of the field. A coin toss decides which team runs which way and which team kicks off. A kick off is similar to the NFL, although the ball is kicked from halfway (50m) and there is no penalty if the ball goes out of bounds, as long as it isn't on the full (without bouncing in play first).
Teams then takes turns attacking and defending. When on the attack, a team's job is to gain more favourable field position so they can attack the opponent's end and hopefully score a try by grounding the ball in their in-goal. A Field goal can also be taken in the form of a drop-kick through the posts. The defensive side must prevent the attacking side from scoring by maintain a solid defensive line, tackling and covering any gaps.
Field position is very important, for both the attacking team and the defending team. The attacking team must maintain possession (not drop the ball or make any mistakes) and use ground gaining maneuvers to gain field position. If an attacking team is in poor field position, a downfield kick (ala punt) can alleviate pressure. When on defence, strong tackling and good discipline can stufle attacking raids and force mistakes.
There are 3 point scoring methods:
The primary focus of scoring is called a Try, the equivalent of a Touchdown. The attacking team must ground the ball either on the opponent's goal-line or in their in-goal area. They must maintain control and stay in-bounds for it to be deemed a try. There are some more complicated rules to it, but I don't want go into them too deeply. A try is worth 4 points. After a try is scored, the scoring team may choose to convert the try by kicking the ball through the goalposts with a tee in line from where the ball was grounded. This is worth 2 points, making a full try worth 6.
If a penalty is ruled, the team infringed may decide to try for a penalty goal which is like a conversion. It is taken with a tee and from where the penalty is awarded. This is worth 2 points.
A Field goal or Drop goal is worth 1 point and is rarely taken. It can be taken anytime during play as long as it's a valid kick. It must hit the ground before contact and must go through the goal posts on the full.
Players in possession may pass the ball as a way of moving the ball across the field and from player to player. A pass is only legal if it is passed backwards or in parallel, it musn't go forward. A forward pass is illegal and the ball goes to the other team. Therefore, all passes are like laterals. Passes can be intercepted by industrious defensive players. The halves are often the best passers and they use the discpline to direct the team around the park by either giving the ball to forwards to gain metreage, or to the backs in attacking maneuvers.
The defensive team's primary way of stopping the attacking team is by tackling the ball carrier as quickly as possible. A tackle is called when the player is forced to a stop either via momentum being stopped or by being on the ground. The tackled player then 'plays-the-ball' and the play continues. The defensive team must retreat 10m after each tackle before advancing, although 2 defensive players can remain close to the tackled player but they must be what is known as 'square' which means in line with them as they 'play-the-ball'. These two players are known as markers and they are most often the players who made the tackle. There are a few illegal tackles which must be avoided (see below), mainly head-high tackles, which is where a tackler strikes the head of the ball-carrier; and the spear tackle, which is where the tackler lifts the ball-carrer up over the horizontal and drops them on their head and shoulders. These tackles draw penalties and sometimes suspensions.
The attacking team has six phases, or tackles, to gain field position or score. The referee keeps track of how many tackles are made by counting them out as they are made. On the 5th tackle the referee signals to both teams where by the tackling team usually kicks the ball either to gain field position, or to attacking their opponents in-goal via attacking kicks. So, similar to the 4 down rule in NFL, just without the first down marker. If a defending player touches the ball but the attacking team remains in possession then the tackle count is restarted.
Now, the play-the-ball is a way of restarting play after a tackle. After being tackled, the player must raise to his feet, place the ball on the ground in front of him and by using one foot, roll the ball backwards to a teammate stationed behind him. This player is known as 'dummy half' and is often the Hooker (it's a position ;)). The Hooker can then run with the ball or pass it to another player. The defensive team must not interfere with the 'play-the-ball' or else they will penalised. They can also be penalised for being to slow in getting off the tackled player which is known as slowing the 'play-the-ball', it's a legitimate tactic, but the defence steps a fine line with the referees it, which is why most penalties are for not letting the tackled player up quick enough. An incorrect play-the-ball also draws a penalty.
Off-side is being in an illegal area. A defending team can be off-side by not retreating the 10m after a tackle, not waiting for the 'play-the-ball' to be complete, or not being 'square' while at marker. The attacking team can be off-side by receiving the ball from a forward pass or by not being behind the kicker of the ball. Off-sides either draw penalties or changes of possession.
A knock-on is when a player fumbles the ball forward or into an opposition player. The ball can go backward and not not be called a knock-on. A knock-on brings on a scrum.
A scrum is a formation of forwards who bind together (as seen below). A scrum was originally developed as a fight for possession as it still is in Rugby Union, but in Rugby League very little pushing occurs and instead it is used as a way of removing the forwards from play for a time so attacking play can be encouraged. The ball is placed between the attacking team's front legs and it is rolled backwards so that it can be picked up from the back. It is rare for the defensive team to win the scrum. Scrums are awarded after forward passes, knock-ons or if the ball goes out-of-bounds.
If a player in possession is tackled in his own goal-line or takes the ball over the dead-ball line, then that team must perform a drop-kick from beneath their own goalposts, giving the opposing team good field position. This is similar to a safety, however know points are awarded, and the kick isn't taken from the 20. The team drop-kicking the ball (known as a drop-out) may regather the ball as long as it goes further than 10m.
Well that's it for now. It's a pretty basic outline of the rules of Rugby League. I plan on doing another post outling the positions of Rugby League, as well as including a bit more on the tactics of the game. I hope you enjoyed this stuff, and I hope it's clear enough. It probably isn't, but maybe you can gleam some understanding off it. Probably the best way to learn the game is by watching, which is what I did with the NFL. Once again, feel free to ask questions in the comment section and I'll answer them as best as I can.
* Note- No images are my property, but rather the proper of their owners. Thanks to Wikipedia who helped greatly on this article.