For some top-tier nations it has been a year of growth and improvement, while others have stuttered in their build-up to the global showpiece tournament that looks on paper to be one of the most open for years.
Eddie Jones refused to get carried away when England were racking up 24 wins from his first 25 games in charge and did not panic when they lost five in a row this year.
It is therefore no surprise he is not getting carried away after an uplifting November series that has propelled them right back into World Cup contention – if they were ever out of it.
After a 2-1 series defeat in South Africa, England followed up with another win over the Springboks, a one-point defeat by New Zealand, a topsy-turvy victory over Japan and a 37-18 thrashing of Australia.
Elliot Daly of England scores a try during the Quilter International match between England and Australia on November 24, 2018.
Image credit: Eurosport
That left them with a 50 percent win rate from 12 games this year but most observers would consider the Twickenham glass to be considerably more than half-full.
A long injury list forced Jones to scour the Premiership for third and fourth-choice players in some positions and that he unearthed potential gems, not least 18-stone Fiji-born winger Joe Cokanasiga, was a bonus as he developed his squad depth.
He now has two months to absorb the latest lessons and will have to hit the ground running away to Ireland in the Six Nations when England can only improve from their dismal fifth-place finish in 2018.
Jones also has four World Cup warm-up matches pencilled in, including another against Ireland at Twickenham.
With France and Argentina struggling for form, England’s pool is starting to look a bit less challenging and, on the back of six successive wins over Australia, two against South Africa and a TMO-inspired loss New Zealand that could so easily have been a victory, they should travel to Japan fearing nobody.
New Zealand's 10-try demolition of Italy in the final game of their end-of-season tour will have done nothing to ease concerns about the two previous matches, where they squeaked past England and lost to Ireland.
The All Blacks remain the benchmark in test rugby and, despite losses to South Africa and Ireland this year, the odds on them winning a third straight World Cup are unlikely to stray much above the 2-1 mark over.
The way England and Ireland were able to emulate the 2017 British and Irish Lions by shutting down the usually free-scoring New Zealand attack, however, will raise fears that a template for beating the All Blacks has been laid out.
The question of whether just one try scored over both the England and Ireland games is more a reflection of an improvement in northern hemisphere defences or poor execution by the All Blacks will probably only be definitively answered in Japan.
The conveyer belt of talent that has given coach Steve Hansen such depth to work with shows no sign of drying up, but he certainly has thinking to do about how to deploy it, particularly in the midfield.
A Six Nations Grand Slam, first test series victory in Australia for almost 40 years and November’s fully deserved toppling of the All Blacks made 2018 the year Ireland became genuine World Cup contenders.
They may have needed world player of the year Johnny Sexton’s stoppage-time drop goal in Paris to kickstart a run of 11 wins in 12, but what followed included commanding victories in London, Melbourne and Sydney.
Tests against the United States, Italy and Argentina meant November was really all about New Zealand and the fact Ireland recoded their second ever victory over the world champions without Conor Murray, Robbie Henshaw and Sean O’Brien spoke volumes for the depth at Joe Schmidt’s disposal.
The world’s second-best side go into World Cup year with proven backup in every position and frontliners like prop Tadhg Furlong, lock James Ryan and winger Jacob Stockdale staking claims alongside Murray and Sexton as the world's best in their positions.
Another Six Nations title – a triumph that would make it four championships in six seasons for Schmidt – would keep the Irish bubbling up around boiling point for their trip to Japan.
Wales completed a clean sweep of their November tests for the first time and end the year with nine test wins in a row and coach Warren Gatland’s World Cup plans firmly on track.
A first victory in 14 attempts over ailing Australia was the highlight but Wales will also be pleased with the way they managed the home wins over Scotland and South Africa.
Gatland has been working towards creating squad depth and this year offered opportunities to a number of new players.
The evidence came as a fringe selection with 14 changes trounced Tonga 74-24 and Wales finish the year third in the world rankings, up from seventh at the end of 2017.
The switch of Gareth Anscombe to flyhalf was a notable success, and with Dan Biggar and Rhys Patchell also in the reckoning there is good competition in a key position.
Averaging almost three tries per game and conceding only 15 points per match shows a team that has improved in attack and defence in the last 12 months.
Their only losses in 2018 came away to Ireland and England, who they are due to meet after the 2019 Six Nations in the build-up to the World Cup for what will be huge tests of their readiness for Japan.
The Springboks may have finished 2018 with a 50 percent win ratio but there is considerably more optimism around the team than a year ago and the real belief they can be World Cup contenders.
Victory over New Zealand in Wellington was the standout achievement and the 2-1 home series win over England in June got new coach Rassie Erasmus’s tenure off to a positive start.
The team has returned to traditional Bok rugby, powerful forwards who carry the ball with ferocity and a strong set-piece platform from which to unleash their backs.
The team is far from the finished article, though, and a feature all through the year has been the number of unforced errors they make which has turned winnable games into defeats.
Among the seven losses, four have been by a margin of five points or less and all were games the team contrived to lose from winning positions, which will be a key area of concern for Erasmus heading into the World Cup.
He has not yet been able to play a full-strength team due to club commitments for overseas-based players and will relish the opportunity to do so in Japan.
The worst test season in 60 years has capped a dispiriting spell for Australian rugby on and off the pitch since the Wallabies lost to New Zealand in the last World Cup final.
In November, a first defeat in 14 tests against Wales, a three-try win over a limited Italy side and a sixth successive loss to England have left the twice world champions sixth in the rankings, a position which if anything flatters them.
The Australians have enough quality through the likes of Israel Folau, David Pocock and Will Genia to always pose a threat, but a consistent 80-minute performance against quality opposition has looked increasingly beyond them.
"If you ain't got the cattle, you ain't got the cattle", is a phrase beloved of losing coaches Down Under and certainly some of the Australia forwards appear to be out of their depth at international level.
Ill-discipline on and off the pitch has contributed to the perception of a dysfunctional set-up but what hurts Wallabies fans most is the sight of their backs approaching the defensive line with apparently little idea of how to breach it.
If coach Michael Cheika survives the review of nine defeats in 13 matches this year, which looks likely, he will have his work cut out to reproduce a repeat of 2015 when he turned a similarly ill-regarded squad into World Cup finalists.
Scotland have proved to be a match for anybody at Murrayfield but a worrying inability to win consistently away from home will be giving coach Gregor Townsend sleepless nights ahead of the World Cup.
Home victories over England, France and Argentina showed their best qualities, but heavy defeats in Wales (twice) and Ireland exposed how much work there still is to do.
A shock 30-29 loss to the United States in Houston in June served as a wake-up call, while arguably their best result came a week later when they defeated Argentina 44-15 in Resistencia.
After a solid Six Nations, the November internationals provided a good gauge for Townsend of his side’s readiness for the World Cup and again they produced a mixed bag.
Defeat by Wales in Cardiff was followed by a resounding success over Fiji based on a strong second-half performance. The final two fixtures brought a loss to South Africa and narrow victory over Argentina.
There have been gains this year, the emergence of Adam Hastings at flyhalf adds depth, and there has been significant rotation among the forwards as Townsend looks to build a powerful pack.
The coach believes he has a squad to compete with anybody in the Six Nations, and therefore the World Cup too, but results don’t fully reflect that yet as Scotland still lack consistency.
France will be happy to see the back of 2018 in which they won three of their 11 tests and suffered a first ever loss to Fiji, a home defeat described as "shameful" by centre Mathieu Bastareaud.
The side must rebuild confidence ahead of the World Cup, though there are other obvious areas of concern.
The French conceded an average of 26 points per game this year, though three tests were away at world champions New Zealand.
If coach Jacques Brunel hoped they had learned lessons from that series, they clearly did not, conceding a last-second try to suffer defeat by South Africa and allowing Fiji to secure that historic victory.
Captain Guilhem Guirado suggested the players had not respected the jersey and were not putting in the required effort following the loss to the islanders, and with the composition of the squad unlikely to change much ahead of the World Cup, that is an area where there is room for big improvement.
Their year highs were a surprise Six Nations home win over England and a comprehensive 28-13 victory over World Cup Pool C rivals Argentina, but it was a season in which France have regressed.
Argentina recovered from a poor start to the year to record their best Rugby Championship performance before losing three games in a row against European opposition.
The big question for coach Mario Ledesma and the Argentina Rugby Union is whether to persist with the policy of selecting mostly home-based players for the international side.
Ledesma took over as coach in August after Daniel Hourcade had overseen just two wins in 17 games and he immediately instilled a new spirit in the side.
The Pumas beat South Africa at home, overcame Australia on the Gold Coast and only failed to record three wins for the first time since they joined the Rugby Championship in 2012 thanks to an epic meltdown at home to Australia.
That loss – the second biggest second-half turnaround in international rugby – took a toll because Argentina have struggled since.
There is no shame in losing to Ireland, but defeats by France and Scotland cast doubts on their chances ahead of the World Cup in Japan, where they have been drawn in a competitive pool with England, France, the United States and Tonga.
A recall of experienced European-based players could mean the difference between winning and losing against the big boys in Japan.
Japan have continued to develop a free-spirited style under coach Jamie Joseph which means they should at least entertain home support next year.
However, the Brave Blossoms’ attacking system, combined with basic tackling errors, leaves them vulnerable in defence and this will be the focus for Joseph as Japan look to reach the quarter-finals for the first time.
Joseph has constantly stressed the need to iron out the inconsistencies that have plagued Japan in recent internationals.
They have been impressive against top-tier nations, drawing 23-23 with France in Paris last year and leading England by five points at halftime, before going on to lose.
They also scored 31 points against a second-string All Blacks side in Yokohama but conceded 69 points in that game and 27 in the narrow win over Russia on Saturday.
If Japan are to progress from Pool A, where they are grouped with Ireland, Scotland, Russia and Samoa, they must show steel in defence to compliment their fluid attack.
Joseph will be buoyed by there being no Top League domestic rugby competition in 2019, leaving him with over nine months to work with his players before the World Cup.
Italy endured another torrid year which highlighted their diminishing status in world rugby and revive questions about whether they add value to the Six Nations.
Conor O'Shea's side managed two wins in 11 games, a narrow success in Japan and a home victory over Georgia, but were otherwise well beaten by all-comers bar a three-point loss to Scotland in Rome.
Their average score across the year was 16-38, although they only scored more than 20 points in a game on three occasions and only once, against Georgia, did they concede less than that number.
That points to a limited attack and porous defence, with little time to fix things before the World Cup.
Italy face New Zealand and South Africa in their pool in Japan and appear to have little prospect of making the knockout rounds.
Their 66-3 loss to the All Blacks showed all their shortcomings as they barely threatened their opponents' line and failed to cope with the speed of the ball in New Zealand hands.