A forward pass seems such a basic part of rugby football's laws. Missing a forward pass can bring great scorn onto the head of a referee. It is seen as simple law, easy to apply.

But is it simple?

These Australian productions may show how difficult it really is.

Firstly, it is about a forward pass, not a forward catch. That means it's about the direction in which the ball leaves the passer's hands.

DEFINITION: THROW FORWARD
A throw forward occurs when a player throws or passes the ball forward. 'Forward' means towards the opposing team's dead-ball line.

For a forward pass, the passer propels the ball forward. It has nothing to do with outside forces on the ball on its journey to the catcher.

To work out the effect of the forward movement on the flight path of the ball is obvious from these clips. If you want to see it in obvious action, throw an object out of the window of a moving car. Throw is backwards and see where it lands.

If the referee, the passer and the catcher are all moving forward, a mistake with a forward pass is less likely to happen than if the call comes from a stationary assistant on the touch line.

The same is true of a stationary spectator who judges whether a pass is forward by where it was passed and where it was caught by players running forward.

A forward pass is not always easy and no referee worth his salt would guess on a forward pass.