IAS mains exam is the subjective examination and consists of two optional papers each of 250 marks. Together these optional subjects are of 500 marks out of the total of 1750 marks ofias mains subjective papers and this gives chances to score higher in mains exam . As this is your choice to select the optional subject it is important to choose the right optional subject in order to maximize your score out of 500 marks which helps in increasing the overall marks of the IAS Mains exam. This makes it very important to choose your optional subject wisely.