The battle for places in the World Cup knockout stages is hotting up.

England and Wales can book their passage from their pools over the next few days, while there are big games coming up for Scotland and Japan, which in turn have an impact on Ireland.

So what are the permutations in each pool? BBC Sport takes a closer look.

What are the rules?

Teams receive four points for a win and two for a draw. A bonus point is awarded for scoring four tries or for a defeat by seven points or fewer.

The winner and runner-up in each pool qualify for the quarter-finals.

If two teams are tied at the end of the group stage then the winner of the match between the two teams will be ranked higher.

If two or more teams are tied then points difference will be used to separate them with various other eliminators used if points differences are equal.

Pool A

Japan v Samoa (5 October): Japan will move back to the top of the table and into pole position for their first World Cup quarter-final if they beat Samoa on Saturday, a result which would end the Pacific Islanders' hopes of qualification.

A Samoa victory would blow the group wide open by moving them ahead of Scotland and level on points with Japan in third, while a bonus-point win would take them into second and the last qualification spot.

If Japan win on Saturday then Scotland would have to beat the Brave Blossoms in a crunch final game on 13 October to progress, with bonus points likely to come into play.

Scotland v Russia (9 October): A Scotland win on Wednesday against Russia would see them move closer to Ireland and Japan, and potentially climb into the top two depending on Japan's result.

Defeat for Scotland would all-but end their hopes of qualification.

Russia are out of the competition but will be keen to register their first point of the tournament.

Ireland will qualify for the last eight with victory over Samoa on 12 October, given Scotland and Japan could not both match the 15 points they would then have.

Remaining fixtures:

Pool B

New Zealand v Namibia (6 October): Defending champions New Zealand may be third in Pool B but they are favourites to take top spot with games against Namibia and Italy to come, having already played - and beaten - South Africa.

A win over Namibia on Sunday will see the All Blacks go top but they would not be mathematically certain of going through until after their final game.

South Africa v Canada (8 October): South Africa can confirm their progression with a bonus-point victory over Canada on Tuesday.

New Zealand v Italy (12 October): Unless Canada shock the Springboks or Namibia beat New Zealand, Italy would have to beat the All Blacks in their final game to progress, and even that may not be enough if Steve Hansen's men claimed bonus points.

Remaining fixtures:

Pool C

England v Argentina (5 October): England will seal their qualification to the last eight with victory over Argentina on Saturday, and all-but end the Pumas' chances of progression.

Victory for Argentina would see them move to the top, level on points with England, while a bonus-point win would take them above the 2003 winners - unless England secure a losing bonus point.

France v Tonga (6 October): If England lose, France can go top by beating Tonga on Sunday. If England win then France will qualify for the next round by beating Tonga.

Tonga have to win both of their remaining games to stand any chance of progressing.

Remaining fixtures:

Pool D

Australia v Uruguay (5 October): The Wallabies will move above Wales into top spot with victory over bottom-place Uruguay - albeit having played a game more. Any win would be enough for qualification if Wales beat Fiji in their next match.

An unlikely victory for Uruguay would take them above their opponents.

Wales v Fiji (9 October): For Wales, it's simple. Beat Fiji and they seal their progress to the next round.

Defeat for Wales would see Fiji move above them.

That would leave Wales, Fiji, Australia, and theoretically Georgia with the chance to reach the knockout stage with the last two fixtures to be played.

Remaining fixtures: