Used to impose a condition on the testator's act of revoking a will. Dependant relative revocation occurs if the condition on which the person based the will was not true so therefore the revocation does not take place. EXAMPLE: T revoked will 1, but will 2 was found to be invalid. Court will apply this doctrine and say that T would have preferred to have will 1 than nothing at all, and will 1 will be found to be valid. Most common situations: replacement of a prior will ineffective; revocation by physical act (some courts ONLY apply this doctrine where prior will was revoked by physical act)