Starting today, teams from 20 nations will convene in 10 locations across France to battle it out for the right to call themselves Champions du Monde.

France will take on Argentina tonight in the 2007 Rugby World Cup's opening game, which will be followed by a further 47 games spread over six weeks before the title is finally decided in the Stade de France on October 20.

France is preparing to go rugby-crazy, with the country's cunning president, Nicolas Sarkozy, desperate to get in on the act in the hopes of profiting from any accruing feelgood factor. A complete rugby novice, Sarko is busily swatting up on the rules and has already persuaded French rugby coach Henri LaPorte to join his government as a junior minister after the competition (though that offer may be mysteriously rescinded if France do not win).

Here, too, rugby fever is about to grip the nation. With Eddie O'Sullivan in charge of possibly the most talented Irish team ever, patriotic fans are daring to hope, and pubs everywhere will be packed to the rafters as Ireland attempt to get out of the so-called ‘group of death' and advance beyond the quarter-final stage – something we have never achieved.

All of this excitement, however, is likely to place you in some awkward positions socially if you haven't a bloody clue what's going on. And those lucky enough to be travelling to France for the games are likely to expose themselves to bodily harm if they announce to Irish supporters around them, who've battled hard to get their hands on tickets, that they can't tell a hooker from a scrum half.

Here, then, with apologies in advance for the term, is our idiot's guide to rugby, the World Cup, and how to bluff your way through it.

The Game

Originating on the blood-soaked playing fields of English public schools, rugby union is mainly played by the former colonies of Britain, as well as by the French, Italians and Argentineans. Among the most ferocious contact sports permitted by law, it has never been short of detractors.

Oscar Wilde once said that rugby was “a good occasion for keeping 30 bullies far from the centre of the city”. Fifteen hefty chaps comprise a team, which attempts to score more points than the 15 brutes who oppose them.

A try (when you touch the ball down behind your opponents' line) is worth five points, a conversion (sending the resulting place-kick between the posts) is worth two, a penalty kick is worth three points, as is a drop-kick.

The players on a team are divided into forwards and backs. The forwards are the extra-huge bunch with missing teeth and cauliflower ears who compete fiercely in scrums, lineouts, rucks and mauls for possession of the oval football, which they then present to the backs.

The backs are the fancy dans who do the flashy runs and intricate passing and generally score the points, but traditionally did not like to get their shorts dirty.

Unlike in soccer, you may pick the ball up and run with it as well as kicking it, though it must never be passed forward.

The Competition

The first Rugby World Cup was staged 20 years ago in Australia and New Zealand, with the All Blacks being the first to triumpantly hoist the Webb Ellis Cup.

Despite being widely considered the best rugby nation in the world, however, they have never won it again, a fact that rankles.

Australia surprised many by winning the competition in 1991. Hosts South Africa were accused by some of skulduggery when half the All-Blacks squad went down with food poisoning the day before the 1995 final, which the home team, the Springboks, narrowly won.

New Zealand were again unexpectedly sidelined in the 1999 competition, by a brilliant France in the semi-final, but the French were then beaten in the final by Australia.

A European side finally won in 2003, when Martin Johnson's bland but ruthlessly efficient England crushed hosts Australia.

The competition, and rugby in general, was changed forever when the game turned professional in 1995.

Since then, rugby has evolved and changed at a bewildering pace, but the World Cup remains the great showpiece of the game.

The Venue

The World Cup is expected to to attract upwards of 350,000 foreign supporters to France, and net the country's economy an astonishing €8 billion.

The games will be staged at 10 venues in France: Paris, Saint- Denis, Lens, Nantes, Bordeaux, Toulouse, Montpellier, Marseille, Saint-Étienne and Lyon.

A small number of games will also be played in Edinburgh and Cardiff. Ireland's group games will be played in Bordeaux and Paris, though thereafter (if there is a thereafter) they will move around the country.

There has been some disgruntlement in France over how the games have been divided between the venues. Marseille, for instance, a town with no interest whatever in the oval ball, is hosting the All-Blacks and a number of important games, while Toulouse, for many the true capital of French rugby, has only been given a small number of games.

However, by spreading the competition across the country, the French Rugby Union are hoping to popularise a sport which is only played seriously in Paris and the southwest of France.

Surviving in France

Conscious of the great number of rugby supporters who are likely to arrive at the tournament without a single mot of French, the French government has had the bright idea of producing a handbook with advice and useful phrases.

Le Kit de Survie en Francais provides a handy glossary of terms covering not just the game itself but social circumstances that surround it. Un essai is a try, une touche is a lineout, un pilier is a prop, ailier is a winger, arbitre is a referee, and cet con d'arbitre is that bloody eejit of a referee, though this phrase does not appear in the French government handbook.

The first half is the premiere mi-temps, the second half the deuxieme mi-temps. And then there's what the French call the troisieme mi-temps – that is, the festivities that traditionally follow rugby matches.

For these situations, the government guide has plenty of advice. Unless you spend all your time in Irish pubs, you'll find your traditional post-match pint being replaced by the more tasteful demi – a half pint. C’est ma tournee means it's my round, though this is academic because French people tend not to buy rounds anyway.

Je suis celibatairé is the French way of announcing that you're single if you feel you're about to get lucky – though the outcome of most World Cup evenings is more likely to be a gueule de bois – a hangover.

Names to drop

If you find yourself suddenly surrounded by festive rugger buggers, there are a number of names you could drop that should enable you to pass muster. On our team, the captain, talisman and international star is Brian O'Driscoll, though his talented partner in the centre, Gordon D'Arcy, is tipped by some to upstage him in the competition.

In the forwards, Paul O'Connell is the leader, and widely considered to be among the best locks in the world. And everyone loves big John Hayes. If you want to sound like you know what you're talking about, you might mutter “God, I hope O'Gara doesn't get injured” – out-half Ronan O'Gara is our only decent kicker, and without him we are royally screwed.

If you want to really sound like you know your stuff, you might add “and why didn't he bring Gleason?” You don't have to know what it means – just say it.

In terms of the other teams, New Zealand's Dan Carter is the back everyone is afraid of, the same team's Richie McCaw the forward universally feared. The most stylish player on the French side is probably Yannick Jauzion, though the star at the moment is the hulking forward Sebastian Chabal, whose size, beard and long hair make him look fittingly Gaulish, and there are rumours he's been offered a part in the next Asterix film.

England, meanwhile, are biting their nails, because Jonny Wilkinson is injured yet again.

The frontrunners

As usual, New Zealand enter the World Cup as runaway favourites. They've looked head and shoulders above everyone else for the past few seasons, and their second 15 would probably beat most teams in the tournament.

As usual, though, the All Blacks' biggest enemy is likely to be themselves. Rugby is a religion in New Zealand, the wearing of the black jersey considered a huge honour, and the pressure on the team is unbelievable. Perhaps as a consequence, the Blacks have earned a reputation as World Cup chokers, and even a team as good as this one is likely to get the jitters in the latter stages of the tournament.

The only side with a squad anything like as strong as New Zealand's is France, and on home soil they will fancy themselves to go all the way.

The French, though, always struggle with consistency, and it's hard to know what to expect from them. Australia are the only team to have beaten the All Blacks this year, and have talent to burn in the back line. Their forwards, however, are another matter. South Africa are currently steady, but unspectacular, but reigning champions England may fancy themselves as outsiders.

And then there's ourselves. Ireland’s Chances? Ireland's form in advance of the 2007 Rugby World Cup could hardly be described as encouraging. During a disastrous warm-up, they twice lost to Argentina during the summer, were easily beaten by Scotland at Murrayfield and only defeated Italy at Ravenhill after the referee decided to declare for Ireland.

Worse still, after some genius had decided that the warm-up should include a match against Bayonne, a French club side well known for their enthusiastic approach to the physical aspects of the game, Brian O'Driscoll was punched in the face and could have missed the whole tournament.

All in all, then, a shambles, prompting some to gloomily predict we'll be dumped out at the group stages. However, there are two ways of looking at it. What would be more typical of Ireland would be to coast brilliantly through the warm-up games before crashing and burning when it really mattered.

We have two easy games to begin with, against Namibia this Sunday, and against Georgia the following Saturday, before we face France (on the 21st), and our old nemesis Argentina (on the 30th).

Our form in the Six Nations and in last year's Autumn internationals was excellent, so if we play to our potential we could even surprise France and top the group, giving ourselves an easier quarter-final.

More likely, though, is the scenario where we squeeze past Argentina to take second spot, giving us a probable quarterfinal against New Zealand, after which all bets are off.