Each of 13 premier League of Legends leagues had a team that won the Spring Split represent them; Europe (EU LCS), South Korea (LCK), and China (LPL) had their teams automatically admitted into the main event whereas the other 10 leagues competed among each other in a "Play-in Stage" with the top 3 teams advancing to join the main event.

[1] SK Telecom T1 from South Korea successfully defended their championship from the previous year, defeating G2 Esports 3–1 in the final.

Based on the result of the MSI and World Championship in 2 years before (2015–2016), 3 teams from Europe (EU LCS), South Korea (LCK), and China (LPL) are started in Main Group stage, 2 teams from North America (NA LCS) and Taiwan/Hong Kong/Macau (LMS) are started in Play-in round 2, and instead of the Mid-Season International Wildcard Invitational in 2015–2016, 8 teams from Wildcard regions are started in Play-in round 1.

São Paulo and Rio de Janeiro were the two cities chosen to host the competition.

GPL of Southeast Asia gets directly spot in Main Group Stage for Summer Split winner and additional spot in Play-in Stage for Summer Split Runner-up at 2017 World Championship.