The Swiss authorities online
If you don't make a will or a contract of succession, succession law determines what happens to your assets after your death (= intestate succession).
The survivors inherit in the order laid down by law. First comes the surviving spouse or registered partner, together with issue (i.e. children, grandchildren and great grandchildren).
If there is no spouse or children, the parents and their issue inherit. If there are no parents or their issue, then the grandparents and their issue inherit. If none of these relatives survives, the entire estate goes to the state.
Cohabitees are not regarded as statutory heirs and thus inherit nothing on their partner's death. Even if there is a will, there is a limit to how much they can inherit if statutory entitlements (minimum amounts under the law of succession) have to be paid to issue or parents.
A statutory entitlement is a guaranteed share of the deceased's estate for the children, parents, spouse and registered partner. Even if you make a will, you cannot override a family member's statutory entitlement. However, heirs can renounce their statutory entitlements by signing an inheritance renunciation contract.
If a will fails to provide the heirs with their statutory entitlements, the will is not automatically invalid, but must be contested in court by the statutory heirs.
The statutory shares specify how the residue of the estate is divided among the heirs once the statutory entitlements have been paid out.
The residue is that part of the estate that is left after the statutory entitlements have been deducted. A testator (person making a will) is free to dispose of this part of his estate as he pleases.
If you have no heirs who are due statutory entitlements, you can dispose of your entire estate as you please.