A will or testament is a legal declaration by which a person, the testator, names one or more persons to manage his/her estate and provides for the transfer of his/her property at death. For the devolution of property not disposed of by will, see inheritance and intestacy.

In the strictest sense, a "will" has historically been limited to real property while "testament" applies only to dispositions of personal property (thus giving rise to the popular title of the document as "Last Will and Testament"), though this distinction is seldom observed today. A will may also create a testamentary trust that is effective only after the death of the testator.

Requirements for creation

Any person over the age of majority and of sound mind (having appropriate mental capacity) can draft his or her own will with or without the aid of an attorney. Additional requirements may vary, depending on the jurisdiction, but generally include the following requirements:

• The testator must clearly identify himself or herself as the maker of the will, and that a will is being made; this is commonly called "publication" of the will, and is typically satisfied by the words "last will and testament" on the face of the document.
• The testator should declare that he or she revokes all previous wills and codicils. Otherwise, a subsequent will revokes earlier wills and codicils only to the extent to which they are inconsistent. However, if a subsequent will is completely inconsistent with an earlier one, the earlier will is considered completely revoked by implication.
• The testator may demonstrate that he or she has the capacity to dispose of his or her property ("sound mind"), and does so freely and willingly.
• The testator must sign and date the will, usually in the presence of at least two disinterested witnesses (persons who are not beneficiaries). There may be extra witnesses, these are called "supernumerary" witnesses, if there is a question as to an interested-party conflict. Some jurisdictions, notably Pennsylvania, have long abolished any requirement for witnesses. In the United States, Louisiana requires both attestation by two witnesses as well as notarization by a notary public. "Holographic" or handwritten wills generally require no witnesses to be valid.
• If witnesses are designated to receive property under the will they are witnesses, this has the effect, in many jurisdictions, of either (i) disallowing them to receive under the will, or (ii) invalidating their status as a witness. In a growing number of states in the United States, however, an interested party is only an improper witness as to the clauses that benefit him or her (for instance, in Illinois).
• The testator's signature must be placed at the end of the will. If this is not observed, any text following the signature will be ignored, or the entire will may be invalidated if what comes after the signature is so material that ignoring it would defeat the testator's intentions.
• One or more beneficiaries (devisees, legatees) must generally be clearly stated in the text, but some jurisdictions allow a valid will that merely revokes a previous will, revokes a disposition in a previous will, or names an executor.

There is no legal requirement that a will be drawn up by a lawyer, although there are pitfalls into which home-made wills can fall. The person who makes a will is not available to explain him or herself, or to correct any technical deficiency or error in expression, when it comes into effect on that person's death, and so there is little room for mistake. A common error (for example) in the execution of home-made wills in England is to use a beneficiary (typically a spouse or other close family members) as a witness – although this has the effect in law of disinheriting the witness regardless of the provisions of the will.

Some jurisdictions recognize a holographic will, made out entirely in the testator's own hand, or in some modern formulations, with material provisions in the testator's hand. The distinctive feature of a holographic will is less that it is handwritten by the testator and often that it need not be witnessed. In England, the formalities of wills are relaxed for soldiers who express their wishes on active service; any such will is known as a serviceman's will. A minority of jurisdictions even recognize the validity of nuncupative wills (oral wills), particularly for military personnel or merchant sailors. However, there are often constraints on the disposition of property if such an oral will is used.

A will may not include a requirement that an heir commit an illegal, immoral, or other act against public policy as a condition of receipt. In community property jurisdictions, a will cannot be used to disinherit a surviving spouse, who is entitled to at least a portion of the testator's estate. In the United States, children may be disinherited by a parent's will, except in Louisiana, where a minimum share is guaranteed to surviving children. Many civil law countries follow a similar rule. In England, a will may disinherit a spouse, but close relations, including spouses, excluded from a will may apply to the court for provision to be made for them at the court's discretion.

Types of wills generally include:

• nuncupative (non-culpatory) will - oral or dictated; often limited to sailors or military personnel
• holographic will - written in the hand of the testator; in many jurisdictions, the signature and the material terms of the holographic will must be in the handwriting of the testator.[1]
• self-proved will - in solemn form with affidavits of subscribing witnesses to avoid probate
• notarial will - will in public form and prepared by a civil-law notary (civil-law jurisdictions and Louisiana, United States)
• mystic will - sealed until death
• serviceman's will - will of person in active-duty military service and usually lacking certain formalities, particularly under English law
• reciprocal/mirror/mutual/husband and wife wills - wills made by two or more parties (typically spouses) that make similar or identical provisions in favor of each other
• unsolemn will - will in which the executor is unnamed
• will in solemn form - signed by testator and witnesses

Probate

After the testator has died, a probate proceeding may be initiated in court to determine the validity of the will or wills that the testator may have created, i.e., which will satisfy the legal requirements, and to appoint an executor. In most cases, during probate, at least one witness is called upon to testify or sign a "proof of witness" affidavit. In some jurisdictions, however, statutes may provide requirements for a "self-proving" will (must be met during the execution of the will), in which case witness testimony may be forgone during probate. If the will is ruled invalid in probate, then inheritance will occur under the laws of intestacy as if a will were never drafted. Often there is a time limit, usually 30 days, within which a will must be admitted to probate. Only an original will can be admitted to probate in the vast majority of jurisdictions – even the most accurate photocopy will not suffice.

It is a good idea that the testator give his executor the power to pay debts, taxes, and administration expenses (probate, etc.). Warren Burger's will did not contain this, which wound up costing his estate thousands.[dubious – discuss] This is not a consideration under English law, which provides that all such expenses will fall on the estate in any case.

Revocation

Methods and effect

Intentional physical destruction of a will by the testator will revoke it, through deliberately burning or tearing the physical document itself, or by striking out the signature. In most jurisdictions, partial revocation is allowed if only part of the text or a particular provision is crossed out. Other jurisdictions will either ignore the attempt or hold that the entire will was actually revoked. A testator may also be able to revoke by the physical act of another (as would be necessary if he is physically incapacitated), if this is done in his presence and in the presence of witnesses. Some jurisdictions may presume that a will has been destroyed if it had been last seen in the possession of the testator but is found mutilated or cannot be found after his or her death.

A will may also be revoked by the execution of a new will. Most wills contain stock language that expressly revokes any wills that came before them, however, because normally a court will still attempt to read the wills together to the extent they are consistent.

In some jurisdictions, the complete revocation of a will automatically revives the next most recent will, while others hold that revocation leaves the testator with no will so that his or her heirs will instead inherit by intestate succession.

In England and Wales, marriage will automatically revoke a will as it is presumed that upon marriage, a testator will want to review the will. A statement in a will that it is made in contemplation of forthcoming marriage to a named person will override this.

Divorce, conversely, will not revoke a will, but in many jurisdictions, will have the effect that the former spouse is treated as if they had died before the testator and so will not benefit.

Where a will has been accidentally destroyed, on evidence that this is the case, a copy will or draft will may be admitted to probate.

Dependent relative revocation

Many jurisdictions exercise an equitable doctrine known as dependent relative revocation ("DRR"). Under this doctrine, courts may disregard a revocation that was based on a mistake of law on the part of the testator as to the effect of the revocation. For example, if a testator mistakenly believes that an earlier will can be revived by the revocation of a later will, the court will ignore the later revocation if the later will comes closer to fulfilling the testator's intent than not having a will at all. The doctrine also applies when a testator executes a second, or new will and revokes his old will under the (mistaken) belief that the new will would be valid. However, for some reason the new will is not valid and a court may apply the doctrine to reinstate and probate the old will, as the court holds that the testator would prefer the old will to intestate succession.

Before applying the doctrine, courts may require (with rare exceptions) that there have been an alternative plan of disposition of the property. That is, after revoking the prior will, the testator could have made an alternative plan of disposition. Such a plan would show that the testator intended the revocation to result in the property going elsewhere, rather than just being a revoked disposition. Secondly, courts require either that the testator have recited his mistake in the terms of the revoking instrument, or that the mistake be established by clear and convincing evidence. For example, when the testator made the original revocation, he must have erroneously noted that he was revoking the gift "because the intended recipient has died" or "because I will enact a new will tomorrow."

DRR may be applied to restore a gift erroneously struck from a will if the intent of the testator was to enlarge that gift, but will not apply to restore such a gift if the intent of the testator was to revoke the gift in favor of another person. For example, suppose Tom has a will that bequeaths $5,000 to his secretary, Alice Johnson. If Tom crosses out that clause and writes "$7,000 to Alice Johnson" in the margin, but does not sign or date the writing in the margin, most states would find that Tom had revoked the earlier provision, but had not effectively amended his will to add the second; however, under DRR the revocation would be undone because Tom was acting under the mistaken belief that he could increase the gift to $7,000 by writing that in the margin. Therefore, Alice will get 5,000 dollars. However, the doctrine of relative revocation will not apply if the interlineation decreases the amount of the gift from the original provision (e.g., "$5,000 to Alice Johnson" is crossed out and replaced with "$3,000 to Alice Johnson" without Testator's signature or the date in the margin; DRR does not apply and Alice Johnson will take nothing).

Similarly, if Tom crosses out that clause and writes in the margin "$5,000 to Betty Smith" without signing or dating the writing, the gift to Alice will be effectively revoked. In this case, it will not be restored under the doctrine of DRR because even though Tom was mistaken about the effectiveness of the gift to Betty, that mistake does not affect Tom's intent to revoke the gift to Alice. Because the gift to Betty will be invalid for lack of proper execution, that $5,000 will go to Tom's residuary estate.

Election under the will

Also referred to as "electing to take against the will." In the United States, many states have probate statutes which permit the surviving spouse of the decedent to choose to receive a particular share of deceased spouse's estate in lieu of receiving the specified share left to him or her under the deceased spouse's will. As a simple example, under Iowa law (see Code of Iowa Section 633.238 (2005)), the deceased spouse leaves a will which expressly gifts the marital home to someone other than the surviving spouse. The surviving spouse may elect, contrary to the intent of the will, to live in the home for the remainder of his/her lifetime. This is called a "life estate" and terminates immediately upon the surviving spouse's death.

The historical and social policy purposes of such statutes are to assure that the surviving spouse receives a statutorily set minimum amount of property from the decedent. Historically, these statutes were enacted to prevent the deceased spouse from leaving the survivor destitute, thereby shifting the burden of care to the social welfare system.