Although studies have yielded a detailed taxonomy of types of slippery slope arguments, they have failed to identify a basic argumentation scheme that applies to all. Therefore, there is no way of telling whether a given argument is a slippery slope argument or not. This paper solves the problem by providing a basic argumentation scheme. The scheme is shown to fit a clear and easily comprehensible example of a slippery slope argument that strongly appears to be reasonable, something that has (...) also been lacking. (shrink)