With 100 days to go until the Rugby World Cup, Sportsmail's Nik Simon takes a look into all the sides involved.

We look at the good, the bad and what their plans are for the heavily-anticipated tournament.

Six Nations teams England, Wales, Scotland, Ireland, France and Italy are all involved as we can start looking forward to the biggest competition in rugby.

ENGLAND

What’s the good news for Stuart Lancaster and his squad?

The Battle Royale for the No 10 jersey is back on after Owen Farrell enjoyed a return to form with Saracens. He was named man of the match in the Aviva Premiership final – beating Bath rival George Ford – and displayed nerves of steel with his goal kicking. While attack-minded Ford is still in the driving seat, Farrell should offer a steady alternative after missing the Six Nations through injury.

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Owen Farrell will be battling it out with George Ford for the No 10 jersey as he makes a return to form

This is the trophy all the nations involved will be hoping to get their hands on at the end of the tournament

And the bad?

Discipline, eligibility and injuries have all had an impact on selection. Hooker Dylan Hartley and centre Manu Tuilagi were both suspended, while flanker Steffon Armitage and full back Nick Abendanon were overlooked because they play for France-based clubs. Ben Foden, flanker Tom Croft and scrum half Joe Simpson are injured, while Danny Cipriani’s chances of making the cut are shrouded in doubt after he was arrested on suspicion of drinking driving.

Dylan Hartley (left) was dropped from the squad after he headbutted Newcastle's Jamie George

What are the plans between now and the World Cup?

Moving away from their main base camp in Bagshot, Chris Robshaw and his Red Rose team-mates will spend two weeks in the ‘Mile High City’ of Denver, Colorado, for high altitude training in July. Lancaster will narrow down his squad between warm-up fixtures against France (twice) and Ireland.

Does Lancaster already have a good idea of his starting XV?

Tom Youngs and Jonathan Joseph are expected to replace Hartley and Tuilagi at hooker and centre, but there are still question marks over the strongest line-up - especially at lock where Courtney Lawes and Joe Launchbury face strong competition from Dave Attwood, Geoff Parling, George Kruis, Ed Slater and Maro Itoje.

Jonathan Joseph was in impressive form during the Six Nations and looks likely to start in the World Cup

Who is the one player they can’t do without?

Robshaw’s captaincy is so finely tuned with Lancaster’s principles and ideas. The Quins flanker is one of the most consistent performers in a white jersey and the omission of Armitage makes his fitness even more important.

WALES

What’s the good news for Warren Gatland and his squad?

Wales are slow starters and will benefit hugely from spending the summer together. Gatland said after the Six Nations: ‘We won’t go into the World Cup with any fears. We have momentum and all the confidence that goes with that. We know that when we spend time together we can play some rugby. There’s no fear for us playing at Twickenham against England or Australia.’

Warren Gatland says his Wales side won't have any fears heading into the World Cup

And the bad?

The loss of stalwart centre Jonathan Davies to a knee injury has been biggest blow to Welsh preparations. Tight-head prop Samson Lee is also suffering from an Achilles injury and Exeter’s Tomas Francis has been called up as cover following the retirement of Adam Jones. Gatland’s decision to leave out Cardiff back-row Josh Navidi raised some eyebrows.

What are the plans between now and the World Cup?

Overseas training camps have been scheduled in Switzerland, Qatar and Poland. Gatland has warned his 47-man squad not to expect a series of ‘holidays’ and will make personnel cuts between warm-up Tests against Ireland (two) and Italy.

Wales' key centre Jonathan Davies is to miss the tournament after suffering a serious knee injury

Does Gatland already have a good idea of his starting XV?

There is a settled feel to the Wales team but one of the key duels is between Liam Williams and Alex Cuthbert for the second winger’s jersey, assuming George North recovers from concussion. Scott Williams is likely to fill in for the injured Davies in midfield.

Who is the one player they can’t do without?

Following the injury to Davies, Jamie Roberts’ presence in the centres will become even more important. He is key to the defensive pattern and is one of Gatland’s most physical ball carriers.

Jamie Roberts will be crucial for Gatland and is a pivotal player for their defensive patterns

FRANCE

What’s the good news for Philippe Saint-Andre and his squad?

There is no sign of revolt just yet. Saint-Andre launched a stinging attack on his players during the Six Nations, claiming he had too many starlets and not enough champions. His squad took the message on board and rediscovered their appetite when they suffered a valiant 55-35 defeat by England on ‘Super Saturday’.

And the bad?

Toulouse winger Yoann Huget was named in the initial 36-man squad but could now face a World Cup ban after footage emerged of him stamping on an opponent’s head. There were some high-profile omissions including Clermont No 10 Camille Lopez, Toulon centre Maxime Mermoz and the Racing Metro wing Teddy Thomas.

Philippe Saint-Andre was highly critical of France during the Six Nations and will be hoping for a response

What are the plans between now and the World Cup?

Les Bleus will convene at their training camp in Marcoussis - 16 miles south of Paris - on July 6. Saint-Andre will cut five players from his group in between a warm-up double header against England and a final preparation Test against Scotland.

Does Saint-Andre already have a good idea of his starting XV?

The head coach will make way for Guy Noves after the World Cup, with Sir Clive Woodward missing out on the vacant role. There are a lot of selection uncertainties, especially over the half-back combination. Sebastien Tillous-Borde, Morgan Parra and Rory Kockott will compete for the scrum-half shirt, while Francois Trinh-Duc, Frederic Michalak and Remi Tales will battle for No 10.

Who is the one player they can’t do without?

Few players have the ability to light up a match like Wesley Fofana. The Clermont centre was one of the stars of the Champions Cup and, if used effectively, can punish the strongest defences with his lightining pace and intelligent running lines.

Wesley Fofana has the ability to win matches for France and he'll definitely be a starter as a centre

SCOTLAND

What’s the good news for Vern Cotter and his squad?

Scottish supporters are still clinging on to the ambitious performances during the autumn internationals. Speaking of the developing squad, 64-cap forward Kelly Brown said: ‘It’s a young side and what’s exciting is that if you look at the star guys from a Scottish perspective – guys like Stuart Hogg, Finn Russell, Mark Bennett – they are young backs and give us something we have maybe not had for a while in flair and cutting edge out wide.’

And the bad?

Former skipper and Saracens back-row Brown was again snubbed as ‘project signing’ Josh Strauss – recruited from South Africa so that he could qualify for Scotland through the residency rule – makes the cut. No 8 Johnnie Beattie, tight-head prop Geoff Cross and winger Dougie Fife were overlooked, while front-row Euan Murray announced his surprise retirement.

Josh Strauss (centre) was controversially picked over veteran forward Kelly Brown in Scotland's squad

What are the plans between now and the World Cup?

After three days at Murrayfield from June 15, the 46-man group will travel to a week-long camp in Fort Romeu on the French-Spanish border, where Paul Radcliffe used to train at 1850m above sea level. Cotter’s side then return to Scotland and will face warm-up Tests against Italy (two), Ireland and France.

Does Cotter already have a good idea of his starting XV?

Injuries have plagued the Scottish midfield and selection will depend on the fitness of centres Alex Dunbar, Mark Bennett and Matt Scott, who have all undergone surgery. Uncapped Strauss will be hoping to challenge for the No 8 berth.

Vern Cotter has seen his midfield ravaged with injury and the selection of his key centres remain a doubt

Who is the one player they can’t do without?

Even if Scotland fail to fire, pint sized full-back Stuart Hogg rarely experiences an off day in his national jersey. He wears his heart on his sleeve and is the side’s most potent attacker with his deceptive speed and dazzling footwork.

KEY DATES IN NEXT 100 DAYS June 15 – Wales begin conditioning training in Vale of Glamorgan June 22 – England gather for first official camp at Pennyhill Park July 1 – Two-week Wales camp in Fiesch, Switzerland July 13 – Two-week England camp in Denver, USA July 17 – Southern hemisphere rivals begin Rugby Championship July 20 – Nine-day Wales camp in Doha, Qatar August 8 – Wales v Ireland warm-up match August 15 – England v France warm-up match August – One-week Wales training camp in Spala, Poland August 22 – France v England warm-up match August 29 – Wales v Ireland warm-up match August 31 – Final 31-man squads announced September 5 – England v Ireland and Wales v Italy warm-up matches September 18 – World Cup kick-off at Twickenham Advertisement

IRELAND

What’s the good news for Joe Schmidt and his squad?

Ireland go into the tournament as Six Nations champions. They did not win the Grand Slam but retired centre Brian O’Driscoll believes that could be a blessing in disguise: ‘In Ireland, we don’t do middle ground, we’re either top of the pile or bottom of the heap. We’ve won the Six Nations and there’s going to be pressure and expectation, but it’s been a little bit tempered by the fact we lost in Cardiff, so hopefully it gives us an opportunity to slip in a fraction more under the radar.’

And the bad?

Captain Paul O’Connell will hang up his international boots after the World Cup and see out his career with Toulon. That’s bad news for Ireland in the long-term but it could be even worse news for Ireland’s World Cup opponents, who will face a team determined to send the veteran out on a high note.

What are the plans between now and the World Cup?

No warm-weather or high-altitude camps have been announced but Schmidt has scheduled training in Galway, Kildare and Cork. The group of players will begin their pre-season training on June 29, before warm-up Tests against Wales (twice), Scotland and England.

Jonathan Sexton (centre) is Ireland's talisman and will be crucial to them winning the competition

Does Schmidt already have a good idea of his starting XV?

The Kiwi coach has a core of experienced players including fly-half Jonathan Sexton, No 8 Jamie Heaslip and lock O’Connell. But there are still some fringe calls to be made, particularly with Simon Zebo, Luke Fitzgerald, Fergus McFadden and Dave Kearney all scrapping for the No 11 jersey.

Who is the one player they can’t do without?

Schmidt’s potent aerial game is focused around Sexton’s kicking. There is a lack of cover for the injury-prone No 10 and Ireland failed to fire when he was rushed in the Six Nations defeat by Wales.

ITALY

What’s the good news for Jacques Brunel and his squad?

Charismatic front-row Martin Castrogiovanni has rebuilt his bridges with selectors after he was dropped during the Six Nations following a serious dog bite on his nose, which required 14 stitches and ruled him out of the Scotland Test.

And the bad?

There are signs of discontent throughout Italian rugby after FIR president Alfredo Gavazzi complained about players after the Azzurri side slipped to 15th in the world rankings. ‘I’m fed up with the pensioners,’ he said. Skipper Sergio Parisse hit back on social media and demanded that his squad are treated with more respect.

Martin Castrogiovanni is back in contention for Italy and his comeback is much needed for Italy

What are the plans between now and the World Cup?

Veterans forwards Parisse and Castrogiovanni will be given an extra month off because of their involvement in the French Top 14 final. The remainder of the 40-man squad will meet in Vilabassa, northern Italy, to begin preparations for warm-up games against Scotland (two) and Wales.

Does Brunel already have a good idea of his starting XV?

The Azzurri side have long-term issues at No 10 and Brunel must decide whether to stick with 17st fly-half Kelly Haimona. Castrogiovanni was axed during the Six Nations but seems to be back in Brunel’s good books.

Who is the one player they can’t do without?

No 8 Sergio Parisse is the heartbeat of the team. He is one of the world’s most gifted players and his captained Italy more than any other player.

THE BIG THREE

NEW ZEALAND

Reasons to cheerful

The All Blacks-studded Hurricanes franchise – including Ma’a Nonu, Conrad Smith and Julian Savea – have been taking the Super Rugby competition by storm. Veteran pairing Richie McCaw and Dan Carter have also been defying their years to keep the Chiefs in contention for the play-offs and head coach Steve Hansen will hope they can keep going for another six months.

Conrad Smith alongside his Hurricane team-mates are key players for New Zealand ahead of the World Cup

Reasons to be fearful

The four-way tussle for the No 10 jersey has been whittled down to three - Carter, Beauden Barrett and Colin Slade - after Aaron Cruden was ruled out of the Rugby Championship and World Cup with torn knee ligaments. Highly rated winger Charles Piutau has also jeopardised his chances after snubbing a new contract in New Zealand for a move to Ulster.

Star player

Giant winger Julian Savea has been hailed by Hansen as the next Jonah Lomu. This will be the 24-year-old’s first chance on the World Cup stage.

AUSTRALIA

Reasons to be cheerful

Toulon pair Matt Giteau and Drew Mitchell could both return to the fold after Wallaby Rugby chiefs opened the door to select certain overseas-based players. Colourful No 10 Quade Cooper has also enjoyed a speedy return to form and fitness with the Reds after fracturing his shoulder in April.

Matt Giteau (right) is expected to return to boost Australia after the overseas-based players rule was lifted

Reasons to be fearful

Selectors seem likely to keep faith in play-maker Kurtley Beale despite his lengthy rap-sheet of off-field misdemeanours. With the Super Rugby campaign still underway, there are also injury concerns over lock Sam Carter, fly-half Matt Toomua and hooker Tatafu Polota-Nau.

Star player

Captain Michael Hooper is an all-action back-row consistently shines through his breakdown work and powerful ball carrying. He will be pushed on by the return of ex-skipper David Pocock from long-term injury.

SOUTH AFRICA

Reasons to be cheerful

The Springboks have an effective working relationship with Europe-based players, as in-form Toulon winger Bryan Habana and Bath flanker Francois Louw will both testify. Skipper Jean de Villiers is ahead of schedule with his rehabilitation after suffering a career-threatening knee injury during the autumn internationals.

Reasons to be fearful

Head coach Heyneke Meyer will be holding his breath after influential No 8 Duane Vermeulen suffered a recent neck injury that required an MRI scan. The forward was ordered to consult a neurosurgeon following intense neck spasms in training last week.

Bryan Habana (centre) has been in terrific form for Toulon and will be one to watch during the World Cup

Star player

Young lock Eben Etzebeth is rapidly becoming the new enforcer in the Springbok pack following the retirement of Bakkies Botha and the waning powers of 38-year-old Victor Matfield.

Ticket update. Any still available? If so, where and when?

Ticket sales broke the 2million mark last week and there are less than 300,000 remaining. Around 60,000 are currently available on the official website – including £250 Category A tickets for England vs Uruguay at the City of Manchester Stadium. The remaining tickets will be released at staggered intervals over the next 100 days.

BEST OF THE REST

FIJI

Who should we be looking out for?

Nemani Nadolo may have been a box-office flop with Exeter but the 20st 2lb winger has become one of the deadliest finishers in Super Rugby. Along with the likes of Vereniki Goneva and Napolioni Nalaga, Fiji have an embarrassment of riches out wide.

Nemani Nadolo (centre) was a flop at Exeter but has been in blistering form in Super Rugby

SAMOA

Sinoti Sinoti has been nicknamed the ‘Tasmanian Devil’ by Newcastle supporters, the winger’s ball-carrying skills earned him a place in the Aviva Premiership Team of the Year. He could partner Tim Nanai-Williams, who has switched allegiance from New Zealand.

ARGENTINA

Who should we look out for?

Outside-half Juan Martin Hernandez was regarded as one of the world’s best players following his cameo at the 2007 World Cup. Since then his career has been blighted but injury but the 32-year-old enjoyed a recent resurgence with Toulon.