Fard al-Kifayah
Defines a communal obligation in Muslim legal doctrine. In juxtaposition to fard al-ayn,
fard al-kifayah is a legal obligation that must be discharged by the Muslim community as a
whole, such as military struggle; if enough members in the Muslim community discharge the
obligation, the remaining Muslims are freed from the responsibility before God. However, if
a communal obligation is not sufficiently discharged, then every individual Muslim must act
to address the deficiency.

Oxford Islamic Studies