IF ADAM AND EVE had decided to split up after decades of acrimony over the apple, dividing their meager property wouldn’t take Solomonic wisdom.

But given the tangle of income and assets that older couples typically have today, ending a marriage later in life can have a financial impact of biblical proportions. One study found that wives who divorce after age 50 see a 45 percent decline on average in their standard of living; husbands see a 21 percent drop.

Avoid a plague of problems by heeding these 10 commandments.

When going through the upheaval of divorce, you may want to keep other aspects of your life the same. But that’s unrealistic because you’ll likely have only half the financial resources.

“You might have to downsize, maybe cut back on your lifestyle,” says Chris Chen, a certified divorce financial analyst in Newton, Massachusetts. “But in most cases you can, in fact, plan so you will not run out of money in your lifetime.”

In many divorces, one spouse prefers to stay in the family home and will give up some retirement assets to buy out the ex. That’s usually a mistake, advisers say, given how expensive a house is to maintain. Plus, it’s a highly illiquid asset that can leave you cash-poor.

“If a home is going to be more than 70 percent of your net worth, you should consider whether you can really afford it,” says Nancy Hetrick, a certified divorce financial analyst in Phoenix.

Where you live largely determines how assets you and your spouse acquired during your marriage will be split. Assets you owned before you wed—and possibly gifts or inheritances you received while married—are considered separate property and won’t be part of the settlement.

In the country’s nine community property states, marital assets are divided evenly. Everywhere else, state guidelines call for an “equitable distribution.”

“Equitable doesn’t necessarily mean 50/50 and doesn’t always feel fair to the parties involved,” says Julianne Incardona, a certified divorce financial analyst in Williamsville, New York.

You can negotiate dividing specific assets as long as the overall value of the distribution meets state guidelines or you agree to a different split.

Along with the house, workplace retirement plans are typically a couple’s most valuable holding. And, like the home, they tend to elicit strong emotions, particularly from the spouse whose name is on the account.

By law, though, both spouses are entitled to a share of retirement assets earned during the marriage, based on state guidelines and, in the case of pensions, each plan’s rules.

Adding to the complexity of pensions: whether the plan includes additional benefits such as health insurance and whether the account holder is already receiving payments. The couple usually has the option to divide benefits, put a lump-sum current value on the pension and split that, or have the account holder buy out the ex.

To execute the division, you typically need a special document called a qualified domestic relations order (QDRO) issued by a court or state agency. Government and military pensions have different mechanisms for splitting.

In negotiating, be mindful of how taxes can affect the value of different assets to make sure one spouse isn’t shortchanged. For example, a savings account with a $100,000 balance is worth more than a traditional IRA with $100,000 in it because withdrawals from the retirement account are taxable and may be subject to an early withdrawal penalty.

“Each spouse should talk to a financial adviser who didn’t work with them as a couple as well as a tax professional to assess tax impact before any decisions are finalized,” says attorney David Horowitz, cochair of the Mediation Committee of the American Academy of Matrimonial Lawyers.

Expecting to get—or pay—spousal support for many years to come? Think again.

“Lifetime alimony has gone the way of the dinosaur,” Hetrick says.

While the specifics differ by state, alimony is now typically designed to last just long enough for a lower-earning spouse to figure out how to become self-supporting.

A lower earner may also qualify for higher Social Security benefits based on the ex’s work record once he or she is eligible to claim, as long as the couple were married at least 10 years; the lower earner’s share of the higher earner’s benefit would be greater than what they would otherwise qualify for; and the lower earner isn’t remarried. The higher earner’s benefits aren’t affected.

If your kids are younger than 18 or haven’t graduated from high school, how much you pay or receive in child support will be determined by a state formula that takes into account each parent’s income and your custody arrangement. In a few places, the age limit is higher: typically between 21 and 23. Most states make exceptions for an adult child with special needs.

Dividing personal property—who gets the furniture, jewelry, artwork, photo albums or the family pet—is a common point of contention.

“When couples fight about their stuff, they’re fighting more about the memories attached to the stuff than about its market value,” says Laura Belleau, president of the American Academy of Matrimonial Lawyers.

Can’t come to an agreement? A judge will decide for you, typically by either ordering you to sell the property in dispute and split the proceeds or take turns choosing items, tossing a coin to see who picks first.

Squash the urge to punish your ex and aim for an amicable settlement.

Contentious divorces often end up in litigation, which can cost up to 10 times as much as mediation. Mediation also gives you a better chance of successfully negotiating matters as you see fit rather than accepting what the court dictates.

“You should be driving the decisions, not the person in the black robe,” Horowitz says.

Once the ink on your divorce decree is dry, make sure to change the beneficiary designation on your financial accounts and insurance policies so your ex doesn’t inadvertently inherit your assets if you die.

As you start to rebuild your life post-divorce, try to focus less on what you have lost and more on what you’ve gained—for example, greater autonomy on how to spend your money. Says Erika Wasserman, a certified financial therapist in Miami, “The freedom in that can be deeply satisfying.”

Longtime journalist Diane Harris was formerly the top editor of Money magazine and deputy editor of Newsweek.