Prenuptial agreements often are considered the purview of the rich and famous. But experts agree they're a necessity for almost anyone marrying later in life.

After all, there are two lifetimes' worth of assets involved. And spouses may have divergent views on what, if anything, to leave kids and grandchildren. Thus, a prenup is a great way to make sure everyone's on common ground.

People often shy away from the subject because bringing up a prenup seems "awfully cold and offensive, and it is," says Mike Martin, president of Financial Advantage Inc. in Columbia, Md., a widower who remarried at 67. But he says: "There's no substitute for openness and candor."

The openness should extend to the extended families, says Joseph "J.J." Montanaro, a Certified Financial Planner with USAA in San Antonio. "Consider conducting a state-of-the-union address," he says.

Linda Suzzanne Griffin, an estate planning attorney in Clearwater, Fla., says bride and groom should hire separate attorneys to draw up the prenup, to reduce the threat of litigation for fraud or coercion.

And don't wait until your rehearsal dinner. Someone signing the night before the wedding can claim duress, potentially opening the door to legal action.