Acid Western is a subgenre of the Western film that emerged in the 1960s and 1970s that combines the metaphorical ambitions of critically acclaimed Westerns, such as Shane and The Searchers, with the excesses of the Spaghetti Westerns and the outlook of the counterculture of the 1960s, as well as the increase in illicit drug taking of, for example, cannabis and LSD. Wikipedia