Licit; legally warranted or authorized.
The terms lawful and legal differ in that the former contemplates the substance of law, whereas the latter alludes to the form of law. A lawful act is authorized, sanctioned, or not forbidden by law. A legal act is performed in accordance with the forms and usages of law, or in a technical manner. In this sense, illegal approaches the meaning of invalid. For example, a contract or will, executed without the required formalities, might be regarded as invalid or illegal, but could not be described as unlawful.
The term lawful more clearly suggests an ethical content than does the word legal. The latter merely denotes compliance with technical or formal rules, whereas the former usually signifies a moral substance or ethical permissibility. An additional distinction is that the word legal is used as the synonym of constructive, while lawful is not. Legal fraud is FRAUD implied by law, or made out by construction, but lawful fraud would be a contradiction in terms. Legal is also used as the antithesis of equitable, just. As a result, legal estate is the correct usage, instead of lawful estate. Under certain circumstances, however, the two words are used as exact equivalents. A lawful writ, warrant, or process is the same as a legal writ, warrant, or process.