The will is a legal instrument that ensures the expression in life of a person’s wishes in relation to the patrimony he intends to leave to his heirs. It is regulated by articles 1.857 and following, of Law 10.406, of 2002 of the Brazilian Civil Code. It is possible to dispose in will of all of its assets, or part of them, and the will may be changed, revoked or replaced at any time, respecting the provisions of the Civil Code. The testament modalities are the public, the closed, the private and the codicil. There are also special wills, that is, maritime, aeronautical and military. The public will is made in the notary’s office, written by the notary of registry according to the will of the testator; it is called public because the will of the testator will be known to others after his death. The closed will is written by the testator or by a person chosen by him and signed by the testator. Its writing must be validated and approved by a notary or a legal substitute in the presence of two witnesses (who cannot be beneficiaries of the document) and the testator . If the testament is proved, it will be kept by the testator and opened after his death, by a judge, before the person who represented the testator in life and the registrar. The private will is written by the testator, read in the presence of three witnesses (who cannot be beneficiaries of the document), who must sign it. It is the simplest of all modalities, but it must be validated by justice through the hearing of witnesses after the testator’s death so that it has legal force. The codicil will is created as an act of last will, done before a person dies, when that testator makes some special provisions, donating furniture, clothes or jewelry, or even, determining the replacement of heirs. It is a model that is in disuse, showing the latest wishes on the deathbed, of a personal interest nature, and cannot have more valuable assets, such as real estate or bank accounts. On special wills, are those made in exception conditions. Aeronautical and maritime wills are of a similar nature, made on board ships or aircraft in motion, in the face of imminent danger, and cannot be made in ports or airports. It will show the testator’s last will, which must be done before the commander and two witnesses. Finally, the military will can be made in cases of war by military personnel or persons involved in the operation of the armed forces in which the testator is unable to make a common will. It must be signed in the presence of the commander or a senior officer and two witnesses or an auditor. If it cannot be written, it can be done verbally and later transcribed by the witnesses. Special wills valid for ninety days if the tester’s death does not occur. In all types of will, consulting a lawyer in preparing it is the best choice for the preparation of a clear document that brings the decisions desired by the testator.