If you die without a Will, which is referred to as dying “Intestate", your net estate will be passed along according to statutory law. In Oregon, this process, known as Intestate Succession, is governed by ORS 112.025 to 112.055.
Only individuals that outlive you (survivors) can inherit your estate under Intestate Succession. Note that children who are conceived prior to your death and are born after your death are considered to be survivors to your estate (ORS 112.075).
The primary beneficiary of your estate will be your spouse, assuming you have one. Note that this does not include a domestic partner. If you leave behind a spouse, the spouse will generally inherit the entire estate. The only exception is if you have any descendants that are not related to your spouse, a child from a previous marriage for example. In this instance, your spouse will only inherit one-half of the net estate.
Any part of your estate that does not pass to a surviving spouse will be distributed according to ORS 112.045. First and foremost, the remaining estate will pass to any of your descendants, such as your children or grandchildren.
Should you have died without any descendants, your remaining estate will generally pass to your parents, subject to one exception. In some circumstances, a potential beneficiary can file a petition demonstrating that one or both of your parents deserted or neglected you. If the petition is accepted by the Court, that parent will forfeit their share of your estate. For the statutory basis for such a petition, see ORS 112.047.
If any portion of your estate still remains, it will be passed to your siblings and the descendants of any of your deceased sibling. If you do not have any surviving siblings, then your estate will be divided among any surviving descendants of your deceased siblings.
If you did not leave behind a spouse, any parents, any siblings, or any descendants of deceased siblings, then your estate will pass to your surviving grandparents. If you leave behind no surviving grandparent, then your estate will pass to the living descendants of any deceased grandparents in equal shares.
Any portion of your estate that is not distributed according to the previous paragraphs will be passed to the State of Oregon under ORS 112.055.