This guide is a complete map of American estate planning and probate, written for lawyers, fiduciaries, and the families they serve. It explains what happens when someone dies without a will under the intestacy statutes, what makes a will valid under Uniform Probate Code § 2-502 and how the harmless-error doctrine of § 2-503 rescues defective ones, and how will contests premised on incapacity, insane delusion, undue influence, and fraud actually get tried. It walks through the revocable living trust and the real probate-avoidance calculus, the irrevocable trusts used for asset protection, transfer-tax leverage, and special-needs planning, and the non-probate transfers -- beneficiary designations, POD and TOD registrations, joint tenancy -- that quietly move most American wealth outside the will entirely. It covers the spousal elective share, powers of appointment, per stirpes and per capita distribution, lapse and anti-lapse, the durable power of attorney, and the health-care directive. It then treats the federal transfer-tax system -- estate, gift, and generation-skipping tax, portability, and the § 1014 basis step-up -- the fiduciary duties of executors and trustees under the Uniform Trust Code and the Uniform Prudent Investor Act, the mechanics of probate from petition to final accounting, and the modern problems of digital assets and inheritable intellectual property. A running hypothetical -- the estate of Eleanor Voss, a photographer with a house, a brokerage account, a small business, and a contested second marriage -- grounds every doctrine in a fact pattern that keeps going wrong.