Cannabis is not a gateway drug. Period. This is not to say, however, that users of cannabis are not more prone to try hard drugs than non-users of cannabis. However, the "gateway" is not the substance itself, but rather the legal status of the substance. Consider: You want to purchase cannabis. Where do you go? A dealer. But not all dealers sell only cannabis. Several also sell cocaine, pcp, opium, meth, ketamine, etc. This means that when some people wish to purchase cannabis, they inevitably come into contact with hard drugs, which increases the probability that they experiment with hard drugs. If cannabis were legalized, however, cannabis users would instead go to Walgreens and never come into contact with hard drugs.