A will serves two important functions when you die; 1) if your children are minors your will nominates the person you want to the court to appoint as guardian of them until they reach adulthood. 2) A will also specifies how you want your “estate” to be transferred at your death. If you pass property via your will, most likely you will need a probate. When used in combination with a living trust, a will acts as a “pour over” device that transfers your non-trust assets to your trust.