What are the situations in which we may change the direction of the Qibla?

Facing the Qibla (definition) is a condition for the validity of prayer, yet it is waived in three situations: inability to face it, such as a sick person who cannot turn towards the Qibla; in cases of extreme fear, like fleeing from an enemy; and in supererogatory (nafila) prayers for a traveler, where they may pray in the direction they are facing. As for someone ignorant of the Qibla, they must exert effort (ijtihad (definition)) and investigate. If they make a mistake after their diligent effort, they are not required to repeat the prayer. However, if they realize their mistake during the prayer, they must immediately turn towards the Qibla.