What Is a Will? Definition, Requirements & How It Works
A last will and testament — usually just called a will — is a legal document that says who gets your property and who should raise your minor children after you die. It is the most basic estate-planning tool, but it only takes effect at death and must usually go through a court process called probate. This guide explains what a will is, the rules for making one valid, and the jobs only a will can do, with citations to the authorities behind each point.
What is a will, in plain terms?
A will is a written instruction for what happens after you die. It names an executor (sometimes called a personal representative) to settle your affairs, directs who receives your property, and — critically — can name a legal guardian for your minor children. The American Bar Association describes the will as the document that lets you “control who gets your property and who will care for your young children” after death. Source: American Bar Association — Estate Planning
Without a valid will, state “intestacy” laws decide who inherits your property and who raises your children. That outcome rarely matches what most people would have chosen. See What Happens If You Die Without a Will for the default rules.
What makes a will valid?
Most states require three things: the person making the will (the testator) must be an adult and of sound mind, the will must be in writing, and it must be signed in front of two disinterested witnesses who do not stand to inherit. Some states also accept handwritten (“holographic”) wills without witnesses, but the rules are strict and vary by state. Source: American Bar Association
A will does nothing while you are alive, and even after death it does not work on its own — a court must admit it to probate before assets can be distributed.
What a will can do (and what it cannot)
Can do: name an executor, direct who inherits specific assets, name a guardian for minor children, and create a testamentary trust for a beneficiary.
Cannot do: avoid probate, manage your affairs if you become incapacitated, or reduce federal estate tax. For those jobs you need a trust, powers of attorney, and beneficiary designations. Learn how the two compare in Wills vs. Trusts.
How a will works with probate
After death, the will is filed with the probate court, which confirms its validity, appoints the executor, and oversees distribution. Probate is public — once filed, a will generally becomes part of the public record — and can be time-consuming and costly. The American Bar Association notes that probate costs commonly fall between 3% and 7% of the gross estate value. A living trust can avoid probate for the assets it holds.
When do you need a will?
Anyone with assets, a home, minor children, or someone who depends on them should have at least a will. If you have children, naming a guardian is the single most important reason. Use our Estate Planning Checklist to see what else belongs in a complete plan, and start a guided plan in the Estate Plan Builder.
Disclaimer
This article is informational only and is not legal advice. Witness requirements and probate rules differ by state and change over time. Before acting, consult a licensed estate attorney in your state. The figures in this article were retrieved on August 14, 2026.
Sources & citations
American Bar Association — Estate Planning: americanbar.org