A recreational drug is most any chemical substance one would choose to consume to enjoy the effect it has on human biology. The most common of these are the depressants and stimulants, many of which are legal and common. A step away from the mainstream lie the also legally obtainable anti-depressants, anaesthetics, and more exotic prescription drugs. Completely unavailable to the populace are the opiates, hallucinogenics, and dissociatives(with the possible exception of very watered down forms in cough syrup and other over-the-counter items). Inside and outside these categories lies many other mystery forms, grouped into the narcotics, which come in varying levels of illegality and potency.
Recreational drug use has been common in various civilizations and still continues to be, despite legislation against most narcotics in many developed countries. This illegalization has gone to extremes in North America, notably because of the USA's famous War on Drugs/War on Some Drugs. Huge amounts of recreational drugs are being seized and destroyed by governments, while even more huge amounts are still distributed and consumed by the populace.
Popular recreational drugs include: