[Bakha]

Armageddon has them in the form of "spice." The funny thing is that they're, from a coding perspective, very similar to potions. They offer various buffs and enhancements depending on the drug. They also have the potential for dependence and overdose. From a roleplaying perspective, though, they're looked at as drugs. They're banned in one city. There's a merchant house that has pretty much made its fortune from harvesting and distributing them, and they're a pretty integral part of the overall culture and atmosphere of the game.

Oh, there is also a hallucinogenic "poison" that some people take recreationally. It causes hallucinations in the form of random echoes to the player.