ACT 0F LAW. An event which occurs in consequence of some principle of law. If, for example, land out of which a rent charge has been granted, be recovered by an elder title, and thereby the rent charge becomes avoided; yet the grantee, shall have a writ of annuity, because the rent charge is made void by due course or act of law, it, being a actus legis nemini est damnosus. 2 Inst. 287.