The hosts are under pressure to perform but they are one of the lowest-ranked teams at the World Cup and the squad has been depleted by injuries. Read a tactical analysis here.
Russia have a clear gameplan and have benefited from a switch to a back three, which most players use at club level. There are also a number of good box-to-box players in the squad.
Russia will sorely miss the injured striker Aleksandr Kokorin while the wing-backs are arguably too old and the centre-backs too young and inexperienced.
Saudi Arabia have been much better in possession since Juan Antonio Pizzi took over from Bert van Marwijk and are less of a counterattacking team now. Read a tactical analysis here.
The three attacking midfielders in Pizzi's 4-2-3-1 – Salem al-Dawsari, Yahya al-Shehri and Fahad al-Muwallad – are talented players who will expect to test any defence in Russia.
The defence is experienced but susceptible to pace and rarely plays against the kind of top-calibre attackers you find at the World Cup.
Egypt's World Cup campaign has, understandably, been overshadowed by the injury suffered by Mohamed Salah. The team need him if they are to get out of the group. Read a tactical analysis here.
Héctor Cúper, as always, builds his team on a solid defence and Egypt conceded only 18 goals in his first 32 games in charge.
With Mohamed Salah in a race to get fit in time for the finals, Egypt may struggle to score with Ahmed Hassan “Koka” often left isolated up front.
The side have developed in recent years, with the midfield far more creative thanks to players such as Federico Valverde, Rodrigo Bentancur and Matías Vecino. Read a tactical analysis here.
The obvious strength of this team lies up front with Luis Suárez and Edinson Cavani forming one of the tournament's most potent partnerships.
No obvious weaknesses but the left-sided midfielder Cristian Rodríguez, at 32, is not getting any quicker and that sometimes leaves the full-back Martín Cáceres exposed.
The European champions are no longer underdogs after their triumph in France but with Cristiano Ronaldo two years older they surely cannot go all the way again. Read a tactical analysis here.
Ronaldo is still the focal point but players such as Bernardo Silva, André Silva and Gelson Martins have gained more experience and are able to support him better up front.
The central defence is a worry with only Pepe - who is not getting any younger - guaranteed a starting place, with Bruno Alves and José Fonte out of form.
La Roja have rediscovered their mojo under Julen Lopetegui, with players such as Isco and Marco Asensio emerging. Read a tactical analysis here.
Spain have one of the strongest squads at the World Cup, with the midfield, led by Sergio Busquets, Andrés Iniesta, David Silva, Asensio and Isco, particularly impressive.
There is not a natural finisher in the squad, such as a David Villa, and Diego Costa has struggled to connect with the midfield when he has played.
The Atlas Lions are back on the biggest stage after a 20-year absence, the former Cambridge United manager Hervé Renard having instilled fighting spirit in the squad. Read a tactical analysis here.
They play with real belief under Renard and Ajax's Hakim Ziyech is one of the most talented playmakers in Europe.
The first-choice goalkeeper, Munir Mohand Mohamedi, started only one league game for Numancia in Spain's second tier and is bound to be rusty.
This is a second consecutive World Cup for Team Melli and Carlos Queiroz says "they have improved". Read a tactical analysis here.
Iran look far stronger up front than they did in Brazil four years ago, with players such as Sardar Azmoun, Alireza Jahanbakhsh, Karim Ansarifard and Saman Ghoddos in good form.
Central defence is a concern as Jalal Hosseini has been dropped, with Queiroz seemingly undecided about who is going to partner Morteza Pouraliganji.
Didier Deschamps has one of the most talented squads at the World Cup but they blew hot and cold in qualifying and seem to lack consistency. Read a tactical analysis here.
The attack is simply frightening with players such as Anthony Martial and Alexandre Lacazette not even making the squad. Three out of Antoine Griezmann, Kylian Mbappé, Olivier Giroud and Thomas Lemar will start up front.
Lack of consistency - they lost to Sweden and drew with Belarus and Luxembourg in qualifying – and the full-backs, Djibril Sidibé and Benjamin Mendy, have just returned from injuries.
Go into the World Cup with a new manager after Ange Postecoglou quit in November. Bert van Marwijk has not had much time to get to know his players. Read a tactical analysis here.
Van Marwijk will aim to tighten the defence and hope that pacy players such as Mathew Leckie and Robbie Kruse can cause damage up front.
This team are not used to playing opponents of the highest calibre and may be overwhelmed against France, Denmark and Peru.
The buildup was dominated by whether Paolo Guerrero would be able to play in Russia and now he is going hopes have been raised back home. Read a tactical analysis here.
Ricardo Gareca has made Peru go back to their roots and they now play with a blend of determination, discipline and creativity. Edison Flores is a wonderful attacking midfielder.
Guerrerro has not played since November and, no matter how important he is to the rest of the team, he will lack match practice when he steps on the pitch in Russia.
Åge Hareide has taken over from Morten Olsen and plays a more direct football than his predecessor while setting up the team to get the best out of Christian Eriksen. Read a tactical analysis here.
Eriksen is one of the best playmakers in Europe and there is pace on the left side with Celta Vigo's Pione Sisto.
Hareide's first-choice defensive midfielder, William Kvist, has lost his place at his club, FC Copenhagen, and may not start in Russia, potentially leaving a gap for opponents to exploit.
Argentina have one of the most fearsome attacks in the world but so far Jorge Sampaoli has not been able to get the players to click. Read a tactical analysis here.
Lionel Messi deserves a mention but the Barcelona forward is backed up by players such as Sergio Agüero, Paulo Dybala, Gonzalo Higuaín and Ángel Di María.
A central defence pairing of Federico Fazio and Nicolás Otamendi does not instil confidence and none of the goalkeepers had more than 10 caps going into the tournament.
Will be playing at their first World Cup after the success in France two years ago but are sweating on the fitness of Gylfi Sigurdsson. Read a tactical analysis here.
The team are more flexible now that Heimir Hallgrimsson is in sole charge and the work ethic and togetherness that saw them eliminate England in France remain.
If Sigurdsson is not 100% then they may struggle to create chances. He is so important to this team.
Zlatko Dalic presides over a hugely talented squad but also one of the oldest in the tournament. Read a tactical analysis here.
Any team with Luka Modric and Ivan Rakitic in midfield are going to have a lot of possession and create chances.
Defence is a concern with Dejan Lovren likely to partner Domagoj Vida in the centre after injury to the veteran Vedran Corluka.
Gernot Rohr seems to have instilled some much-needed team spirit and discipline into the Super Eagles squad since taking over in 2016. A hugely talented group of players.
Central midfield with Mikel John Obi as the conductor and Ogenyi Onazi and Wilfred Ndidi as ball winners offers excellent ballance.
The goalkeeping situation is far from ideal with the 19-year-old Francis Uzoho likely to start despite limited game time for Deportivo La Coruña and a mistake in the recent friendly against England.
What a turnaround since the humiliating 7-1 defeat against Germany four years ago. Coach Tite has made them into one of the favourites to win the tournament.
The attack is formidable with Neymar back after injury and backed up by players such as Philippe Coutinho, Willian, Gabriel Jesus and, of course, the left-back Marcelo.
Dani Alves's injury is a huge blow, partly because of his influence in the dressing room but also because he is better than his likely replacement, Danilo.
Not much has changed from the squad that contested Euro 2016 but there seems to be a bit more togetherness about them these days.
The team collective. The coach, Vladimir Petkovic, says the team have grown together and keep working hard for each other.
Goals can sometimes be hard to come by and Haris Seferovic, who is likely to start up front, has not had the best of seasons at Benfica.
Óscar Ramírez has continued in Jorge Luis Pinto's footsteps by focusing on a solid defence and quick counterattacks, just as they did four years ago in Brazil when they reached the last eight.
The defence stands out, with Giancarlo González of Bologna and Espanyol's Óscar Duarte having got better since Brazil 2014.
The team, whether set up in a 4-5-1 or 3-5-2 formation, are fundamentally not set up to attack and if they fall behind they may struggle to turn matches around.
The former Serbia international Mladen Krstajic has changed things since taking over from Slavoljub Muslin in October last year and favours a 4-2-3-1 formation.
The Lazio midfielder Sergej Milinkovic-Savic is one of the most sought-after players in the world and could, together with Dusan Tadic, ensure Serbia are an attacking force to be reckoned with.
The back four could struggle against pacier sides and they will also be without the injured centre-back Matija Nastasic.
One of the favourites to win the World Cup, the strength in depth is remarkable. Won the Confederations Cup last summer in Russia with half of the first team rested.
The midfield is a smorgasbord of talented players with Toni Kroos, Sami Khedira and Mesut Özil and Thomas Müller hopeful of a starting berth. Leroy Sané didn't even make the squad.
There is possibly a lack of leadership in the squad compared with the last World Cup when Joachim Löw had players such as Bastian Schweinsteiger, Philipp Lahm and Per Mertesacker to count on.
El Tri have reached the last 16 of the past six World Cups and the nation expects them to get out of the group this time too.
The attack looks potent with Javier Hernández the obvious focal point but the PSV Eindhoven winger Hirving Lozano may well prove to be an even bigger threat.
Osorio has not yet found his ideal No 6, with Héctor Herrera often leaving too much space between defence and midfield, which the oppostion can exploit.
This will be the first major tournament Sweden have contested without Zlatan Ibrahimovic since 2000. Focus has shifted towards the collective.
They are extremely organised under Janne Andersson, who prefers a straightforward 4-4-2, which was enough to finish above the Netherlands in the group and eliminate Italy in the play-offs. Emil Forsberg offers unpredictability.
The fear is that the forward-line will struggle. Marcus Berg plays in the United Arab Emirates these days and Ola Toivonen has been out of the team at Toulouse.
Having qualified playing 4-2-3-1, Shin Tae-yong has recently flirted with a back three and two strikers but has not quite found the right balance.
The forward line is pacy with danger across the line. Son Heung-min showed this season that he can play in a number of positions and did well when he led the line in Harry Kane's absence at Spurs.
Lee Keun-ho and Kwon Chang-hoon were ruled out just before the World Cup and that has placed even more pressure on Son.
Roberto Martinéz has a host of talented players to choose from and the team are ranked among the top five in the world.
The front three, Eden Hazard, Romelu Lukaku and Dries Mertens, are of the highest quality and they are backed up by Kevin De Bruyne in midfield.
There may be some tension in the squad if they do not hit the ground running, with De Bruyne having criticised Martínez's tactics after last November's wild 3-3 draw with Mexico.
Will be at their first World Cup after dramatically finishing above USA in Concacaf qualifying.
This team will not give up without a fight. They will work hard, sometimes on the limits of the rules, as they showed in a friendly against Denmark in March.
Román Torres, the forward who was arguably the star of the qualifiers, has been innjured and will not travel to Russia in the best shape.
Won African qualifying group A, finishing above DR Congo, Libya and Guinea, to reach the country's fifth World Cup.
Wahbi Khazri has had an outstanding season on loan at Rennes from Sunderland and will lead the attack.
Injury to the squad's most creative player, Youssef Msakni, has left a huge creative gap for Nabil Maâloul to fill in attacking midfield.
Went through qualifying without a single defeat – as is their wont – and there is a feeling Southgate's team have got more about them than Roy Hodgson's in 2016.
Several players have picked up pleasing high-pressing habits from managers such as Jürgen Klopp and Mauricio Pochettino while Harry Kane is lethal up front.
The three-man defence favoured by Southgate nowadays has not been tested in competitive games against the toughest opposition.
Ranked in the top 10 in the world, Poland won eight of 10 qualifiers and scored an average of 2.8 goals per game.
Robert Lewandowski is one of the most lethal strikers in the world and should be ably backed up by Arkadiusz Milik, who is back from two serious knee injuries.
Had the worst defence of all European group winners in qualifying and Adam Nawalka is considering using a back three instead of his favoured 4-2-3-1.
Back at the World Cup after a 16-year absence but the coach, Aliou Cissé, has been heavily criticised because of his perceived negative tactics.
The team have an impressively strong spine with Kalidou Koulibaly in defence, Idrissa Gana Gueye and Badou Ndiaye in midfield and Sadio Mané up front.
There is a feeling in Senegal that Cissé does not get the best out of the attacking talent at his disposal and the friendly draws against Uzbekistan and Bosnia-Herzegovina in March did nothing to change that.
One of the teams of the tournament in Brazil four years ago, when they reached the quarter-finals. José Pékerman remains in charge.
The country's two superstars, James Rodríguez and Radamel Falcao, have had good seasons at club level and arrive in Russia in good shape.
David Ospina has suffered from not playing regularly at Arsenal and has made high-profile mistakes for the national team recently.
Made the surprise decision to relieve Vahid Halilhodzic of his duties in April and replace him with the veteran Akira Nishino.
The high-profile trio of Keisuke Honda, Shinji Kagawa and Shinji Okazaki are back after being sidelined by Halilhodzic and should lift the team on and off the pitch.
Nishino has tried 3-4-2-1 – a formation used by some top clubs in the J-League – in a few friendlies but the team have struggled to adapt to the changes.