Haven't a clue what's going on? Here's an idiot's guide to understanding rugby.
The basics To start with, a rugby ball is oval, not round, and it doesn't roll. Two teams of 15 players battle it out over two halves of 40 minutes.
The rules The aim of the game is, of course, to score more points than your opponent by touching down over the opposing side's line. The players can run with the ball under their arm and pass it using their hands or feet. The opposition can stop them in full flight by tackling. Like love, rugby can hurt! It might seem strange that the players pass the ball backwards when they should be getting it upfield, but the key to rugby is that forward passing is forbidden (kicking the ball upfield is allowed). And if players break this rule, they're punished and have to form a scrum. Which is never a bad thing for the view of all those well-developed thighs, we reckon.
Scoring Scores like 33-18 are quite normal. Unlike football, you score more than one point at once: 5 for a try, 2 extra for a conversion, 3 for a drop-goal and 3 for a penalty.
Now you're armed with the basics you can surprise him with your knowledge and more importantly, enjoy the World Cup!