( Things that make the Salat void )
Twelve things make the Salat void:
1. If during the Salat, one of the conditions that is necessary for the Salat to be correct goes away, then the Salat is void. For example, one realizes that he is praying in a usurped place, a place that is stolen, or does not have the permission of the owner.
2. One's Wudhu becomes void.
3. Placing one's hand on top of the other hand, just like most of the Muslims who are not Shi'a do.
4. Saying "Amin" after reciting Surah al-Fatiha.
5. Intentionally or unintentionally turning away from the Qiblah, or turning to the right or left.
6. Speaking intentionally during the Salat.
7. Intentionally or unintentionally laughing out loud, during the Salat.
8. Intentionally crying over matters of the world.
9. Breaking the form of the Salat, for example clapping, jumping up in the air, or anything else.
10. Eating and drinking.
11. Having a doubt in a two Rak'at Salat whether one has prayed two or three Rak'at, or in the first two Rak'at of a four Rak'at Salat.
12. Adding or subtracting any of the Pillars of the Salat, whether it be intentionally or unintentionally. Adding or subtracting those things that are not a Pillar of the Salat, if done intentionally (then it makes the Salat void; but if done unintentionally, then it is not a problem).