Any prayer becomes invalid and nullified by any act of the following:
1.To anticipate the Imam in any act or movement of prayer;
2.To eat or drink during the prayer;
3.To talk or say something out of the prescribed course of prayers;
4.To shift the position away from the direction of Qiblah in Mecca; unless it is impossible to the worshipper to face the Qiblah;
5.To do intentionaly and unnecessary any noticeable act or movement outside the acts and movements of prayer;
6.To do any thing that nullifies the ablution, e.g., discharge of urine, stool, gas, blood, etc.; unless due to a medical condition not in the worshipper’s control, in this case the worshipper needs to perform ablution only once for every Fard (obligatory) prayer, and he should not repeat the ablution to perform the Sunnah prayer relative to that Fard prayer.
7.To fail in observing any of the essential acts of prayers, like standing, reciting the Qur’an, Ruk’u, Sujud, etc.; unless for reasons of disability or physical ailment.
8.To uncover the body between the navel and knees during the prayer in the case of males; and in the case of females, to uncover any part of the body, except the face and the hands.
Any prayer which becomes invalidated must be repeated properly.