The slippery slope, sometimes known as the Camel's Nose*, fallacy occurs when a writer wishes to argue against something and suggests that if it were to be allowed to happen, a series of progressively increasing unacceptable events will result.  The slippery slope fallacy is the illegitimate use of the if-then logical operator.

Example:

If the union concedes to management's wage concession this year, then every following year, the company will demand more and more concessions until we are working for free. (But, if the company returns to profitability, we may get a better package in the next contract!)

Strategy: Identify the false relationship and show that even if the first event happens, the last event will not necessarily result.

* The Camel's Nose Fallacy is that should the camel get his nose under the tent flap, it won't be long until the whole camel is inside the tent.