If you die without a will or trust, the state determines who will be in charge of administering your estate as well as who will receive your estate assets. This distribution plan can be found in the intestacy statues of each state.
In Arizona, for example, without a valid will or trust, the intestate estate passes to the surviving spouse. HOWEVER, if you pass away and you have separate children that are not the children of your surviving spouse, your children are entitled to your interest in the community property subject to probate and your spouse is entitled to your separate property subject to probate. Imagine your surviving spouse having to share your community property home with his/her step children?
any part of a decedent’s estate not disposed of by will or trust, the surviving spouse is entitled to the community property of the decedent and the decedent’s separate property IF there are no separate children who are not the children of the surviving spouse and the decedent. If there are separate children, the children of the deceased spouse are entitled to one-fourth of the decedent’s separate property.