It is true that there are variations in rugby field sizes. This is especially true when you deal with the ones in the lower grades. Of course, the dimensions of the field will have some sort of effect on any player's game. However, there are also official dimensions for a standard rugby field established by the International Rugby Board.
If you compare the different sized rugby fields everywhere, you'll notice that there isn't a set of minimum figures given by any authority. However, you can be sure that there are maximum lengths for each of the dimensions of every field. For example, there is no minimum length for the field of play but the maximum length is set at 100 meters. This is the actual maximum distance between the two goal lines on the opposite sides of the field.
The half-way line is exactly what it is, a line that is located at the middle or halfway into the field. Yes, the line is located in the middle of the field. However, the actual distance between the half-way line and the goal line is relative to the actual length of the field. For instance, on a standard 100 meter pitch, the half-way line will be located 50 meters away from each goal line.
However, there are also pitches of varying lengths, such as an 80 meter pitch. Of course, the half-way line will be located at the very middle of the two goal lines, which is exactly 40 meters from the goal lines. Players and coaches should assess the actual length of the field the players are to cross when making their game plans.
Rugby Field Width
The maximum width of any rugby field out there is 70 meters. This is the standard maximum width for competitions. However, at the lower levels, the width will be less than the official standard width. This is yet another reason why a coach should make an actual check on the field's dimensions.
Take note that if your players are used to playing on wider fields, they might feel cramped when playing on narrower fields. Some find it easier to defend in narrower fields but players should expect to cover a lot more ground when defending in a wider field.
Even if you check with the IRB standards, there are no official dimensions for the in-goal area. As you might expect the width will vary depending on the actual width of the entire rugby field. However, the depth of the in-goal area is set from 10 meters to 22 meters. The posts have a minimum height of 3.4 meters with posts that are 5.6 meters wide.