The International, the annual tournament for Valve's Dota 2, featuring dozens of players and millions in prize money, was put on hold today when a distributed denial-of-service (DDoS) attack slammed the game's servers. Unlike the games of the past, played over local area networks (LAN), Dota 2 requires a connection to the internet, making it susceptible to these sorts of online attacks. The technical difficulty raises a question about how Valve will hold future tournaments, namely why hasn't the publisher created a self-contained version of Dota 2 that doesn't rely on the game's main servers.
The rest is here:
Valve’s $18 million Dota 2 tournament delayed by DDoS attack