"Tests will be performed at our discretion at any time during tournament days, and will take place in a designated testing area," the league said on Reddit. "Naturally, player's privacy comes first."
Notably added to the list is Adderall, the attention deficit disorder drug that can enhance reaction times and focus significantly, especially if used by someone who does not have it prescribed. Of course, valid prescriptions are still allowed but voluntary notification by the players must be made to the ESL including a physician's note. Marijuana is also banned on competition days, but is fine for recreation (if it is legal in your state or country to do so).
Each penalty for breaking the rules will be made on a per-case basis and can "range from getting prize money / tournament points deducted, to disqualification and up to a two year ban from ESL events."
Source: