People have strong feelings about negotiation. Sometimes those feelings erupt. The 2011 sale of a $3 million brownstone in New York’s Greenwich Village almost fell apart because of a dispute over an old washing machine that the sellers had removed from the premises two days before the closing. Stephen Raphael, the lawyer for the owners, told the New York Times that it really wasn’t worth fighting over, “but the buyers had already felt pressured to up their offer and to concede many things, and this was the last straw.”

A version of this article appeared in the January–February 2013 issue of Harvard Business Review.