What is the ruling of Islamic law regarding someone who concluded the prayer with two salaams to the right, or made the salaam to the left and forgot to make the salaam to the right first?

The validity of prayer is not affected by violating the recommended manner of salutation (Taslim). So, whoever says the two salutations to their right or left, or the first to their left and the second to their right, their prayer is valid, though they miss out on theفضل (virtue). It is even more valid for someone who forgot and initiated the first salutation to their left. The first salutation is obligatory, and the second is recommended.