A logical fallacy where a series of increasingly bad conclusions are shown to follow from a premise. The problem is that the conclusions usually don't follow with 100% probability, and are usually proved by assertion.

Example: see almost any hasty argument on one of the topics mentioned in a writeup above ;)

To prove the use of Slippery Slope fallacy, prove that the conclusions don't necessarily follow 100%. If they do follow 100%, then it's not a fallacy.