Going forward, the ESL will conduct skin-swab tests at its tournaments that will yield results within minutes. It mays also introduce urine and blood tests, if recommended to do so by either Germany's Nationale Anti-Doping Agentur or the World Anti-Doping Agency, with which the league is working on its drug policy.
"This is something we've suspected would become an issue in the future," ESL Vice President of Pro-gaming James Lampkin told CNBC.
"We knew we would have to deal with this when the stakes were high, when people would be looking for an illegal way to take off the edge. That time came now, which is why we're moving so quickly."
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The Adderall-taking gamer, Kory "SEMPHIS" Friesen, was a professional player of "Counter-Strike: Global Offensive" and a member of the Cloud9 gaming team. According to his Twitter account, he is from Abbotsford, Canada.
Lampkin said that Friesen was no longer part of the team roster, but that without concrete evidence, the ESL would not be taking action against Cloud9 over doping allegations.
Cloud9 and Friesen did not respond to interview requests from CNBC by press time.
Patrik Sattermon, chief gaming officer of professional video-gaming team FNATIC, said that he believed that doping was rare in e-sports and that he had rarely heard competitors talking seriously about taking performancing-enhancing drugs.
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Overall, he said he welcomed the ESL drug testing policy.
"I'm curious to see how it's applied globally, and we'd like to see some sort of cooperation between organizations," he told CNBC.
While ESL is one of the largest gaming organizations, tournaments are run by several international groups including South Korea's World Cyber Games and the US-based Major League Gaming.
E-sports have come quite a long way, but it's a landscape with few international standards, and with millions of dollars now being doled out in prize money.
"The timing is right (for drug testing)," Sattermon said. "Someone needs to set the standard and lead the way. "