Do biological and adopted children have equal rights to the estate of deceased parents?

The same rights, unless a will states a differently. * In any US state it depends upon whether the person died intestate or if there was a valid Will. There are no laws that require a parent to leave any assets or property to children whether said children are biological or adopted. That being the case a parent(s) can legally exclude any or all children from a Will if they so choose. If the person dies without a Will the state's probate succession laws apply and adopted children are treated the same as biologcial children.