Both Harry and Kit smoke several times, most of the secondary characters also do so at least once. Scenes take place in bars and casino-like clubs, where many of the patrons smoke.
Alcohol (liquor for most) is consumed in social settings and a few other scenes.
Cocaine is briefly seen and tasted in one scene.
A secondary character smokes his cigarettes like they were joints (seen from a distance). It's never made clear whether it's tobacco or weed.