The Slippery Slope fallacy is asserting that a relatively small first step inevitably leads to a chain of related events culminating in some significant impact/event that should not happen, thus the first step should not happen. While this fallacy is a popular one, it is, in its essence, an appeal to probability fallacy.

Example: If Christians are allowed to deny service to those whom they don’t agree with, it will give everyone a license to discriminate.