What's changed?
Rugby World Cups have, since 2003, seen 20 teams competing, with two teams progressing from each of the four pools and straight into the quarter-finals.
However, in 2027 there are four further teams added, and instead of increasing the number of teams in each pool from five to six, the decision has been made to make it six pools of four, with the top two in each progressing to the round of 16, where four of the best third-place teams will join them.
That means there will be some relatively easier games for some in the round of 16, but things will once again heat up at the quarter-final stage where we've already been promised a likely showdown between four-time winners South Africa and three-time champions New Zealand.
Where could the home nations meet?
The four British and Irish sides are neatly placed in two of the groups, with Ireland and Scotland meeting in Pool D, while England and Wales are in Pool F.
Ireland and Scotland to meet in Perth
There will be a big clash on 10 October when Ireland take on Scotland at Perth Stadium, as the loser faces a challenging knockout campaign to say the least.
The winner of that game will likely top Pool D, the prize for which is a last-16 tie with a team that finishes third in one of the other pools. The likely quarter-final opponent from there would be Argentina, and if they get past that, then they will probably face either England or Australia in the semi-finals.
On the flip side, the loser will likely finish second in the group and head to the other side of the draw, which would see them facing France in the last 16.
Win that one, and they will potentially face Wales or Fiji in the quarter-finals, which is a winnable game, but that would set up a semi-final against the winners of the anticipated quarter-final between the Springboks and the All Blacks.
So even though Argentina have been a famous bogey side for Ireland at World Cups, they would certainly take that path over the one that would see them face two of the other three teams in the top four of the current world rankings. Scotland, meanwhile, after failing to make it out of the group stage in the last two editions, will relish having that Ireland game as a primary target on which to focus their ambitions for the rest of the campaign.
England could send Wales on a dismal journey
England face Wales in Sydney on 16 October in what is the final group-stage game for both. The winner will head to Perth to take on the team that finishes second in Pool B for the round of 16, which looks like it will be Italy or Georgia, unless either side can topple the Springboks.
Win that game and a potential quarter-final against either hosts Australia or Japan awaits, and thereafter a semi-final against Argentina or the winner of the game between Scotland and Ireland.
All of those games are immanently winnable for a team like England, if not Wales. If, as would be predicted on current form, Wales lose to England and finish second in the group, they will head to the other side of the draw.
First up on that side is a round-of-16 game against the team that finishes second in Pool C, which is likely to be Fiji. Admittedly a bogey side for Wales in recent times, but not a bad first game in the knockouts.
But that's as good as it gets on that side, because if they get through that game, they will face either France or the loser of the game between Ireland and Scotland in the quarter-finals. Get past that result, and a semi-final against either the Springboks or All Blacks awaits.
So you'd have to say that losing that pool will likely result in the end of the road for Wales, and potentially for England as well if it's a case of France in the quarter-finals and South Africa or New Zealand in the semi-finals.
Still a long way to go
Those paths obviously bank on other results as well, all of which could throw things. If Australia beat neighbours New Zealand in Pool A, that would send the All Blacks over to the 'easier' side of the draw, which would decrease its relative ease.
Wales, while hoping to beat England, also have to show some consideration for a tough game against Tonga. USA or Samoa could beat Japan in Pool E, putting the Brave Blossoms on a course as one of the third-place teams, which would throw the cat among the pigeons. Georgia beating Italy in Pool B could do the same.
One result that could annoy fans of Ireland, New Zealand, France and South Africa would be Scotland beating Ireland in Perth, because it would put Ireland on a collision course with the other top-four teams.
The 2023 World Cup was criticised for forcing those four teams - the top four at the tournament as well - to face off at the quarter-final stage, giving the teams on the other side of the draw a better time of it.
But there is still a long way to go before that first round of knockouts takes place, not least of which is the upcoming inaugural finals weekend of the Nations Championship, which will give us an early indicator of who to look out for ahead of Australia 2027.