If you are going to South Korea to attend the Blizzard Worldwide Invitational, you would like to know the admission is free.  However, you still have to register to get a pass.
Drysc: “For those interested in attending this year’s World Wide Invitational from May 19-20 at the Olympic Gymnastics and Fencing Stadiums in Seoul, Korea, we wanted to inform everyone that entrance to the event is free of charge, and only registration at the event is necessary to attend. Please bring a picture ID (such as a passport) once you arrive at the event in order to receive an entrance pass.

The event will feature exciting e-sports tournaments, unique panel discussions held by Blizzard developers on various topics, and several hands-on attractions.

We hope to see you at the event!”