DDoS attack takes down Valve's $18m Dota 2 International e-Sports tournament

Matches set to be played in front of thousands at Seattle's KeyArena delayed due to DDoS attack

A video game tournament with a prize pot of $18m was delayed because a distributed denial-of-service (DDoS) attack caused the game's servers to fail.

The International Dota 2 Championships tournament is set to take place over six days in the KeyArena in Seattle, Washington, with the winning team set to bag over $6m.

But despite the 16 international e-Sports teams being inside the same room, they still require the internet to play competitive matches against each other for the tournament.

That meant the second day of the Dota 2 Championships was delayed due to what Valve's on-stage commentators confirmed to be a DDoS attack against the game's main servers. It meant the players set to compete on stage in front of a sold-out crowd of thousands at the KeyArena couldn't begin their scheduled matches.

The attack also meant that those looking to watch the Dota 2 International Tournament on online streaming services such as Twitch and YouTube had to twiddle their thumbs until the server was back up and running normally.

That might not sound significant, but over 20 million people watched last year's Dota 2 championship and the lack of action is likely to have disgruntled sponsors.

Following a three-hour delay, matches were able to restart after Valve managed to overcome the DDoS attack.

However, the cyber attack raises questions for the games company as to why it hasn't worked to prevent this sort of incident occurring by separating its International Tournament servers from regular Dota 2 servers.

The DDoS attack against Valve's Steam servers is far from the only time cyber vandals have targeted video games companies. Last year, Sony's PlayStation Network - the backbone of its PlayStation 4 ecosystem - was taken down in a DDoS attack attributed to the Lizard Squad hacker group.