As previously mentioned in this thread, you are not allowed to throw the ball forward and catch it. You can pass it sideways or backwards to yourself, but any deliberate throwing/knocking of the ball forwards is illegal.I do realise that these intricate laws must make it difficult for newcomers to the sport, but they are essential to stop people just throwing the ball over the defensive line, running though (the defence wouldn't be allowed to tackle someone without the ball) and catch it the other side. It would make a mockery of the game!I suppose you're allowed to head the ball, but trying to head a rugby ball and maintain any control would be difficult. Honestly never seen someone purposefully doing so before.