At common law, there is no legitime; the Statute of Wills, 32 Hen. VIII c. 1, provided for the unfettered distribution of a decedent's entire estate; a testator is entitled to disinherit any and all of his children, for any reason and for no reason. Most jurisdictions in the United States have enacted statutes that prohibit a testator from disinheriting a spouse, or provided that in the event of such an will the spouse may elect to "take against the will" and claim a statutory share of a decedent's estate. This is done as a substitute for the common law rights of dower and curtesy.
In Louisiana, up until recently, the situation was different. In Louisiana the legitime operated to prevent a parent from wholly disinheriting his children, who were called forced heirs. If there was one child, that child must receive at least 25% of the decedent's estate. If there were two or more children, they must receive at least 50% of it among themselves. Similar provisions prevented a decedent with living parents from disinheriting them.
Current Louisiana law provides for a forced share if the decedent's children are under 24 years of age, or are permanently unable to take care of themselves.