Fornication

Imam Sadiq (as) has been reported to have said,

An illegitimate child is just like any other person. He will be rewarded for a good deed and will be punished for a bad deed.

وَلَا تَقْرَبُوا الزِّنَا إنَّهُ كَانَ فَاحِشَةً وَسَاءَ سَبِيلاً، اسراء:32