The Rugby League World Cup will, for the first time, stage men's, women's and wheelchair tournaments at the same time when England hosts the 2021 edition - making it "the most inclusive" edition ever.
Men's and women's events were held simultaneously in 2017 in Australia but the wheelchair events will be added in three years' time.
A public draw for each of the three tournaments is due to be held on November 27 in the host country.
Details for all three disciplines have now been officially released by the Rugby League International Federation's (RLIF) Board, which has approved the draw and format details for the tournament.
The men's tournament is set to feature 16 teams, in four pools, with the top two from each group qualifying for the quarter-finals.
The women's and wheelchair competitions will have eight teams in two groups, with the top two from each group making it straight through to their respective semi-finals.
The England men's side are due to open the tournament and will be seeded as A1 alongside holders Australia, New Zealand and Tonga.
The second pot will feature Papua New Guinea, Samoa, Fiji and Lebanon with the final two pots for the draw made up of the remaining qualifying teams, based on their world ranking, including the two most recently qualified sides, France and Wales.
The women's tournament is scheduled to begin on men's quarter-final weekend with the English side opening proceedings.
Holders Australia will be seeded B1 with New Zealand being in pot two.
The remaining five spots will be filled by an expression of interest process taking place in 2019.
The wheelchair tournament will follow the same format, with England kicking-off the event.
Current holders France will be given B1 for the draw.
Jon Dutton, chief executive of the 2021 tournament, said: "One of our main aims was to hold the most inclusive Rugby League World Cup of all time and I'm delighted that we have that confirmed.
"With England opening each of our three tournaments, it will be a fantastic spectacle.
"It was important for us to demonstrate a commitment to tier-two nations and growing maturity for the World Cup with a clearer format.
"I am delighted that we have worked with the RLIF Board to be able to share the format and structure of our three tournaments at this early stage."
Nigel Wood, chief executive of the RLIF, added: "The RLIF board are very impressed with the progress that RLWC2021 is making.
"To be able to announce this news across all three competitions, three years before their respective World Cup Finals, demonstrates further progress for the international game and we look forward to ongoing collaboration with the RLWC2021 organisers."
The Rugby League World Cup is the pinnacle event of rugby league, globally contested every four years.
The 2021 edition will be the most visible rugby league event in history, it is claimed, with all 31 games in the men’s competition being broadcast live on the BBC and every second of the women’s and wheelchair competitions being free to watch online.