As the lineout is a primary factor in distinguishing rugby from several other oval ball sports it is probably not surprising that it occupies such an important part of the game of rugby.
Add in thirteen pages of lineout rulings and there is a lot of things for referees to be aware of and possibly rule on.
After last week's column on the lineout I thought I would leave it off the list of possible topics for a few weeks, but it didn't take long for some other lineout issues to be brought to the forefront of things to talk about.
One occurred in a game I was watching at Spriggens Park last Saturday and the other came from a discussion I had with two spectators who had watched the Kaierau game against Taihape, also on Saturday.
Last week's column looked at the quick throw-in as a tactic used by many teams in the modern game.
But there is also a quick lineout option that is occasionally used to good effect.
A quick lineout occurs when a lineout is in the process of being formed and the thrower throws the ball in before all the players are ready for the lineout.
There must be at least two players from each team lined up on the mark-of-touch in readiness for the ball to be thrown in between them.
Once that obligation has been met the thrower can throw the ball in at any time.
What usually happens is the thrower waits until all his team (and usually the opposing lineout players) are standing ready for the ball to be thrown in.
The thrower's team call out their code for where the ball is to be thrown, while the opposition try to decipher the code and counter the opposing jumpers.
What happened in the Spriggens Park quick lineout was the thrower threw the ball in before everyone (especially the opponents) were ready.
It is a really good tactic, as it brings in the element of surprise that immediately puts the opposition on the back foot.
The thrower threw to the front man of his team, who caught the ball and was off up the field before the opposition could say "Hang on, we're not ready."
Unfortunately for the thrower's team, neither was the referee, who was quietly walking through the lineout along the mark of touch with his back to the players and the touchline.
He turned around once players started yelling and rushing around and blew his whistle to stop play because he had no idea if the lineout had been taken correctly, which, from my observations, it had.
The Kaierau incident was one that occasionally occurs when a team takes a quick throw-in.
The ball had been kicked downfield by a player from one team, all of whose side were therefore offside because they were in front of the kicker.
An opposing player picked the ball up after it had gone over the sideline and threw the ball in to a team mate, who was quickly tackled by one of the kicker's offside players who happened to be nearby.
Some may argue once the ball went into touch that was the end of the phase of play, so the offside rule no longer applied to those players who were offside in front of the kicker.
Under this track of thought, the throw-in would be the beginning of a new phase (lineout) and everyone reverted back to being onside. The tackler could therefore legally tackle the opponent.
But, because the throw-in was taken quickly, it is not considered a new phase of play but rather a continuation of the last phase.
The offside players, when the kick was taken, gained a huge advantage from that offside play.
What they should have done, if they were more than 10m back from where the ball crossed the touchline, is remained stationary until they had been put onside.
If they were less than 10m from where the ball went out (as the tackler apparently was) they needed to retire to at least 10m back from that point.
Once an opponent had run 5m with the ball, or had kicked the ball, they would be back onside in this case. A pass does not put them onside.
Another tricky thing for referees is the driving maul from the lineout.
To do this correctly, the ball must be moved to the back of the maul as quickly as possible. Other players cannot join in front of the ball.
What sometimes happens is the ball is passed back to the receiver, who then joins the players in front of him, effectively causing an obstruction.
The opponents can attempt to sack the lineout drive, but this must be done immediately when the maul forms, otherwise they are deemed to have caused the maul to collapse and are penalisable.
Or they can choose not to contest the throw and subsequently withdraw from the lineout after the ball has been caught.
If the opposition have transferred the ball back with the intent to drive forward, a ruling of accidental offside applies because the ball is at the back of the group of lineout players of the catcher's team.
If they don't transfer the ball to the back, then the opponents can then attempt to go for the ball and tackle the ball carrier, but only after they start advancing with the ball.
Whatever happens after the ball crosses the touchline the referee has a lot of things to rule on.
Once upon a time, the lineout was a good time for the referees to relax and catch their breath while the players got ready for the ball to be thrown in.
But not these days because of all the options teams now have.