For a long time now, StarCraft II players have been asking Blizzard for variety in competitive multiplayer. Traditional ladder matches are fun and all, but they can get a little repetitive — especially when you're addicted to StarCraft and play like four hours a day.
Enter tournament mode. In addition to overhauling macro mechanics (RIP MULEs), the next patch for the Legacy of the Void beta will add automated tournaments, allowing people to compete in both three- and six-round competitions through a computer-assisted system that will match up players of similar skill levels. Blizzard originally announced plans for these tournaments in November 2014 — now, they're finally happening.
When the tournament feature goes live, you'll be able to access this sign-up page, which will show you when the next tourney starts and how you can enter:
Everything's pretty standard from there — matches will be capped at 25 minutes (which, as Blizzard points out, equates to 35 minutes in Heart of the Swarm time because of the changes they have made to Legacy's clock) and you'll progress through the tournament's rounds like you would in any other organised competition. There will be two types of tournaments, Blizzard says: Three-round tourneys (available Monday-Thursday) and six-round tourneys (available Friday-Sunday).
There's still no release date for Legacy of the Void, but Blizzard has said they're aiming to get it out by the end of this year. The new patch should be out within the next few days, if not sooner.