It’s not often that a lawyer gets the chance to leave $4.5 billion on the table. But when plaintiffs’ lawyer Brian Panish proposed to forgo most of the punitive damages his client had won in a suit against General Motors, he joined a small but significant trend: offering to trade big punitive damages for a corporate defendant’s promise to make changes that may prevent future injuries.

In addition to Mr. Panish’s clients, two plaintiffs in separate cases represented by a single Corpus Christi, Texas, firm have offered similar deals–to forgo millions rather than billions–in an auto crash case and a gas rig explosion.