League of Legends World Championships: What you need to know
The quarter-finals of the 2015 League of Legends World Championships are being held in London this year.
Thousands of fans will be packing into Wembley Arena to watch some of the world's best summoners (and their chosen champions) strutting their stuff.
The action will be fast and frantic. And there's quite a large prize up for grabs.
Here's our guide to the event and who's playing.
First up, a "summoner" is what they call the players because they summon spells.
The format (get ready for lots of numbers)
Sixteen teams from across the world made it through to the League of Legends World group stages.
Earlier this month in Paris they competed in four groups made up of four teams, with the top two teams in each group making it through to Wembley.
Now they face a straight knockout competition to make it to the semi-finals to be held next week in Brussels.
Over four days the teams (which consist of five players each) will compete in a best-of-five matches format.
Beat the other team and you're still in the competition, lose and it's time to go home.
Origen: One of the newest teams on the European e-sports scene, they were set up by an ex-member of one of League of Legends' most successful sides.
Fnatic are the Manchester United of the game, and Enrique "xPeke" Cedeno Martinez was one of its stars. He left the team in 2014 for a fresh start setting up Origen.
Made up of players from France, Germany, Denmark and Spain Origen are the only team without an Asian player on their roster.
Flash Wolves: One of the most formidable team in recent League of Legends history the Flash Wolves take on Origen for a semi-final spot.
Originally founded in 2013 the team from Taiwan finished in first place in the Taiwan regional finals.
Watch out for their 17-year-old player Yi-Tang "Maple" Huang, one of the youngest players in the competition.
SKTelecom: The team from Korea are former World Champions they won the competition in 2013.
They struggled in last year's competition losing out to eventual champions Samsung White in the Korean regional heats.
Sang-hyeok "Faker" Lee is known as "The Demon King" in Korea because of his dominance in the game. He's one of the greatest summoners of all time.
Ahq e-Sports Club: Taking on former champs SKTelecom will be the boys from Taiwan.
Often overshadowed by local rivals and 2012 World Champions The Taipei Assassins they want to prove they're good enough to win the title.
Chia-Wei "Alibis" Kang was a founding member of the team he's been trying to be crowned world champion with Ahq e-sports Club since 2010.
Fnatic: The first ever League of Legends World Champions and the game's equivalent of football super-team Real Madrid.
They have loyal fans and the team's roster, while being very different to the original line-up, is packed full of talent.
Bora "YellOwStaR" Kim is on of the longest serving League of Legends professionals.
EDward Gaming: The Chinese team will be taking on the former champs Fnatic in Wembley.
Created in 2013 to become the premier e-sports team in China Edward has gathered what's been called a "super team" of players.
Watch out for Kim "Deft" Hyuk-kyu regarded as one of the most aggressive players of the game.
KT Rolster: The Korean team have lost some of their best players in recent years.
Despite the loss of key members of the squad they've managed to win their regional qualifiers to reach this far in the competition.
Sang-moon "Nagne" Kim is famous for a showdown in the 2013 World Championships with SKTelecoms summoner "Faker" Lee.
KOO Tigers: The last match will be an all-Korean affair with the Tigers taking on KT Rolster.
The KOO Tigers only formed in 2014 pulling players ion form a variety of other teams.
Understated Seo-haeng "KurO" Lee has quietly earned a reputation as one of the best players in his position in Korea.
Players all want to win the Summoners Cup and scoop the pride that comes with it.
$1m (£645,000-ish) in prize money for the winning team, second place gets $250,000m (£161,000-ish).
They also get a place in the history books as the best team in the world.