Moroccan inheritance law classifies heirs into three distinct categories. The first is that of heirs with fixed shares, or ashab al-furud (fard heirs). These individuals are entitled to a determined fraction of the estate as set by the Quran and Sunna. The fixed shares provided for are: one half (1/2), one quarter (1/4), one eighth (1/8), two thirds (2/3), one third (1/3), and one sixth (1/6). Among fard heirs are the wife, husband, daughter, son's daughter, mother, father (in certain cases), grandmother, full sister, paternal sister, and uterine brother.
The second category is the 'asaba (residuary or agnatic) heirs. These heirs receive what remains of the estate after the fixed shares have been allocated. In the absence of fard heirs, they inherit the entire estate. There are three sub-categories: 'asaba bi nafsih (residuary in his own right, such as the son, full brother, paternal uncle), 'asaba bi ghayrih (residuary through another, such as the daughter in the presence of a son), and 'asaba ma' ghayrih (residuary with another, such as the full sister in the presence of a daughter).
The third category, dhawil arham (cognate relatives), only inherit in the total absence of fard and 'asaba heirs. This category includes the children of the daughter, children of the sister, maternal uncle, and paternal aunt. Article 371 of the Moudawana provides that, when there are no fard or 'asaba heirs, the estate passes to dhawil arham according to a priority order defined by law.
The mechanism of hajb (exclusion) plays a central role in determining effective heirs. An heir may be fully excluded (hajb hirman) or have their share reduced (hajb nuqsan) by the presence of a closer relative. For example, the full brother is excluded by the deceased's son, and grandchildren through a son are partially excluded by direct children. Mastery of hajb rules is essential for any inheritance calculation.