Gaming organisation ESL announced an anti-doping policy under which competitors will banned from using marijuana during competitions.
Under new rules there will be ban of substances on a list compiled by German agency Nationale Anti-Doping Agentur (Nada) and the World Anti-Doping Agency (Wada).
ESL said that it will test the players during competitions through saliva-based tests for performance-enhancing drugs, starting with its ESL One Cologne event this month.
If the player is tested positive then the punishment will vary from deduction of prize money to disqualification and up to a two year ban from ESL events.
However, according to ESL’s head of communications Anna Rozwandowicz the company will look at each case individually and protect player privacy.
Rozwandowicz said: "ESL One Cologne will only see randomised tests, however we don’t want to exclude the possibility of performing a larger number of tests among all/majority of players at a later stage.
"Should the testing policy and method change, we will inform the players accordingly."
The agency’s anti dope policy has been subjected to debate after one of its high-profile players Kory ‘SEMPHIS’ Friesen used the Adderall drug during a competition.