ou probably assume, like millions of other Americans, that when you die your nearest living relative inherits your assets. That's what you get for taking a common sense approach to issues that involve the government.

Thanks to the laws of 50 different states, nothing could be further from the truth.

It's true that your insurance policies, retirement plans and any trusts you have set up automatically go to the beneficiaries you have named. But what happens to the rest of your property? Anything you own exclusively (and sometimes jointly) is part of "probate" property, meaning that it has to pass through a meticulous legal process to get from your name to those of your loved ones. If you have made a will, the language in that document controls who gets what. If you don't have a will, guess who has control: your state legislature.

State legislatures have enacted a series of laws that govern estates and those with no valid will. You might assume that if you are married and have no children, your spouse gets everything. Guess again. Laws vary widely from state to state, but your spouse might get half and your parents the rest. If you're single and have a child, half may go to your offspring, and the rest to your siblings or your parents. And if you are married with children, your spouse probably won't get it all. He or she may only get one-third of your estate, while an individual (typically a lawyer) named by the probate court controls the rest. That individual, whom you may have never met, is hired to represent the interests of your children - even though you logically expect your spouse to do exactly that upon your death. This means that your spouse may have to petition the court just to use some of this money for basic needs, such as tuition, clothing or music lessons.

Your will not only controls where your money goes, but your financial assets such as your bank accounts and your house. You can also use your will to bequeath antiques, family heirlooms or items of sentimental value to the individuals you choose. In your will you can also make bequests to charitable organizations. People have even made provisions for the care of their pets, with any money left over after Rover's death going to the next beneficiary in line.

Many times, wills are used to keep beneficiaries from their own weaknesses. You can arrange that your profligate sister only gets a fixed amount of money each year. Or you might give your children control of their assets in stages of their lives. For example, the first one-third of their inheritance becomes available at age 25 with the remainder available in equal disbursements at ages 35 and 45. Usually, these goals are accomplished by using your will to set up trusts. If you do, you also will need to name a trustee.

There are also other key non-material benefits to having a will. First, if you have children, your will allows you to name a guardian or guardians for them. Otherwise the court decides. You also name the executor of your will, who not only helps shepherd your assets through the probate process, but who serves as your team's quarterback for all other aspects of your estate (insurance policies, trusts, etc.).

The last important reason to have a will is that it is a place to state your wishes for loved ones, and also to put certain conditions on their inheritances. You may state that if your spouse remarries, he or she forfeits the right to your money or you may actually encourage your spouse to remarry by specifically saying so in the will. You can disinherit a relative who might otherwise be entitled to part of your estate, such as a child. However, no state allows you to disinherit your spouse.

Wills can be as simple as a three-paragraph, one-page declaration of wishes, or as complicated as a 65-page document that sets up multiple trusts, trustees and guardians . Whatever you do about your estate planning, do something.

Even if you feel your situation is complicated, at least put a basic will in place now. You can always amend it (attach a codicil ), or even create an entirely new one. The important thing is to have a will.

There are all sorts of reasons - financial, emotional, parental, even revenge - to have a will. Your will is your voice speaking from the grave, continuing to control assets, events and people, years after your death. That's more power than a lot of us have in our lifetime, so why not take advantage of it in death?