The term soft drug is given sometimes to a range of drugs that are supposed to be less harmful than other drugs, called hard drugs. The main difference is that soft drugs cause only psychological addiction, while hard drugs also cause physical addiction. Examples of soft drugs include: cannabis and hallucinogens such as LSD, psilocybe cubensis, and peyote. Drugs such as alcohol and nicotine, although generally legal, are not considered "soft". Other hard drugs are cocaine and opiates such as heroin and morphine.

The difference between soft drugs and hard drugs is important in the Dutch drugs policy, where soft drugs are dealt with much lighter (up to being for sale as such in clearly recognisable coffeeshops) than hard drugs.