I read somewhere, especially during the First Opium war many of the Chinese soldiers were addicted to the opium the British were trading. British soldiers would enter forts and all they could find would be the remnants of smoking pipes and whatnot. I thought that could lead to a pretty fun skirmish game of a group of Chinese soldiers, having hidden, are now trap in a fort with the British! They would then have to escape using various methods else face capture by the British.