Each team plays four matches, one game against each side, to determine which two teams will go through to the knockout stages.
Four points are awarded to a side for a win, two points for a draw and zero points for a loss.
There are also bonus points available during the pool stage. One bonus point is awarded for scoring four tries, irrespective of the result. One bonus point can also be gained by the losing side if they lose by seven points or fewer.
How many pools are there?
There are four - A, B, C, D - containing five teams each.
Which pool is England in?
Eddie Jones' side feature in Pool C along with Argentina, France, USA and Tonga.
How many go through in each group?
The top two make it through to the quarter-finals, taking place on October 19 and 20.
What are the latest standings?
Fixtures and results
Pool A fixtures
- Japan 30 Russia 10... Tokyo Stadium... Friday, September 20... 11.45am BST... (ITV)
- Ireland 27 Scotland 3... International Stadium Yokohama... Sunday, September 22... 8.45am BST... (ITV)
- Russia 9 Samoa 34... Kumagaya Rugby Stadium... Tuesday, September 24... 11.15am BST... (ITV 4)
- Japan 19 Ireland 12... Shizuoka Stadium Ecopa... Saturday, September 28... 8.15am BST... (ITV)
- Scotland 34 Samoa 0... Kobe Misaki Stadium... Monday, September 30... 11.15am BST... (ITV)
- Ireland 35 Russia 0... Kobe Misaki Stadium... Thursday, October 3... 11.15am BST... (ITV)
- Japan 38 Samoa 19... City of Toyota Stadium... Saturday, October 5... 11.30am BST... (ITV)
- Scotland 61 Russia 0... Shizuoka Stadium Ecopa... Wednesday, October 9... 8.15am BST... (ITV)
- Ireland vs Samoa... Fukuoka Hakatanomori Stadium... Saturday, October 12... 11.45am BST... (ITV)
- Japan vs Scotland... International Stadium Yokohama... Sunday, October 13... 11.45am BST... (ITV)
Pool B fixtures
- New Zealand 23 South Africa 13... International Stadium Yokohama... Saturday, September 21... 10.45am BST... (ITV)
- Italy 47 Namibia 22... Hanazono Rugby Stadium... Sunday, September 22... 6.15am BST... (ITV)
- Italy 48 Canada 7... Fukuoka Hakatanomori Stadium... Thursday, September 26... 8.45am BST... (ITV 4)
- South Africa 57 Namibia 3... City of Toyota Stadium... Saturday, September 28... 10.45am BST... (ITV)
- New Zealand 63 Canada 0... Oita Stadium... Wednesday, October 2... 11.15am BST... (ITV 4)
- South Africa 49 Italy 3... Shizuoka Stadium Ecopa... Friday, October 4... 10.45am BST... (ITV 4)
- New Zealand 71 Namibia 9... Tokyo Stadium... Sunday, October 6... 5.45am BST... (ITV)
- South Africa 66 Canada 7... Kobe Misaki Stadium... Tuesday, October 8... 11.15am BST... (ITV 4)
- New Zealand vs Italy... City of Toyota Stadium... Saturday, October 12... 5.45am BST... (ITV)
- Namibia vs Canada... Kamaishi Recovery Memorial Stadium... Sunday, October 13... 4.15am BST... (ITV)
Pool C fixtures
- France 23 Argentina 21... Tokyo Stadium... Saturday, September 21... 8.15am BST... (ITV)
- England 35 Tonga 3... Sapporo Dome... Sunday, September 22... 11.15am BST... (ITV)
- England 45 USA 7... Kobe Misaki Stadium... Thursday, September 26... 11.45am BST... (ITV)
- Argentina 28 Tonga 12... Hanazono Rugby Stadium... Saturday, September 28... 5.45am BST... (ITV)
- France 33 USA 9... Fukuoka Hakatanomori Stadium... Wednesday, October 2... 8.45am BST... (ITV 4)
- England 39 Argentina 10... Tokyo Stadium... Saturday, October 5... 9am BST... (ITV)
- France 23 Tonga 21... Kumamoto Stadium... Sunday, October 6... 8.45am BST... (ITV)
- Argentina 47 USA 17... Kumagaya Rugby Stadium... Wednesday, October 9... 5.45am BST... (ITV 4)
- England vs France... International Stadium Yokohama... Saturday, October 12... 9.15am BST... (ITV)
- USA vs Tonga... Hanazono Rugby Stadium... Sunday, October 13... 6.45am BST... (ITV)
Pool D fixtures
- Australia 39 Fiji 21... Sapporo Dome... Saturday, September 21... 5.45am BST... (ITV)
- Wales 43 Georgia 14... City of Toyota Stadium... Monday, September 23... 11.15am BST... (ITV)
- Fiji 27 Uruguay 30... Kamaishi Recovery Memorial Stadium... Wednesday, September 25... 6.15am BST... (ITV 4)
- Georgia 33 Uruguay 7... Kumagaya Rugby Stadium... Sunday, September 29... 6.15am BST... (ITV)
- Australia 25 Wales 29... Tokyo Stadium... Sunday, September 29... 8.45am BST... (ITV)
- Georgia 10 Fiji 45... Hanazono Rugby Stadium... Thursday, October 3... 6.15am BST... (ITV 4)
- Australia 45 Uruguay 10... Oita Stadium... Saturday, October 5... 6.15am BST... (ITV)
- Wales vs Fiji... Oita Stadium... Wednesday, October 9... 10.45am BST... (ITV)
- Australia vs Georgia... Shizuoka Stadium Ecopa... Friday, October 11... 11.15am BST... (ITV 4)
- Wales vs Uruguay... Kumamoto Stadium... Sunday, October 13... 9.15am BST... (ITV)
Knockout rounds, key dates:
- The Quarter-Finals are on October 19-20.
- The Semi-Finals are on October 26-27.
- The Bronze Final is on November 1.
- The Final is on November 2.
Who progresses to the knockout stages?
The top two teams from each pool progress into the quarter-finals.
The winner of Pool C faces the runner-up in Pool D in quarter-final 1.
The winner of Pool B faces the runner-up in Pool A in quarter-final 2.
The winner of Pool D faces the runner-up in Pool C in quarter-final 3.
The winner of Pool A faces the runner-up in Pool B in quarter-final 4.
The winner of quarter-final 1 plays the winner of quarter-final 2 in the semi-finals.
The winner of quarter-final 3 plays the winner of quarter-final 4 in the semi-finals.
There is a Bronze Final between the two losers of the semi-final fixtures as well as the Final.
Dates of knockout matches
- The Quarter-Finals are on October 19-20.
- The Semi-Finals are on October 26-27.
- The Bronze Final is on November 1.
- The Final is on November 2.