The game has an in-game clock, and there are regular "timed" events that take place throughout the game that are basically a hard cap on when you can realistica

The game has an in-game clock, and there are regular "timed" events that take place throughout the game that are basically a hard cap on when you can realistically win the game. (i.e.: To earn gold & experience, you must kill 'creeps', and waves of creeps spawn every 1 minute in game. You'll need a certain amount of gold & experience to have the in-game strength to take down defensive towers.) An average human game lasts 30 to 45 minutes. If OpenAI simulated 1,000,000 games, that'd be over 28 years of non-stop gameplay to a human.