A will is a written instrument containing directions on how the assets and property of the testator (individual creating the will) shall be divided upon his or her death. Wills can also contain instructions regarding the care of minor children, gifts to charity, and formation of posthumous trusts. In order for a will to be legally valid, the testator must sign the will in the presence of two witnesses, and he or she must be mentally competent and not acting under duress or under the controlling influence of another. Wills must pass through a somewhat expensive and court-supervised process called probate before property can transfer at their direction.