Law
The Parol Evidence Rule and Its Exceptions in Contract Interpretation
Quick fact
The parol evidence rule can bar evidence of a prior oral promise even if it was made in good faith and relied upon, unless an exception such as ambiguity or fraud applies.
Why this is interesting
You've signed a written agreement, but the other party claims that a verbal promise made before signing is part of the deal. Can they enforce that oral promise? Surprisingly, often they cannot—but sometimes they can.