UPSC CSE Mains examination is subjective in nature .The main objective of Mains examination is to check indepth understanding and knowledge of a candidate in the variety of subjects. A candidate can answer questions easily without any specialized knowledge if he hasgeneral understanding of the issues, good writing skills, equipped wih factual data, ability to analyze & take decision objectively precisely. For Optional Subject, the candidate should be equipped with comprehensive knowledge which is basic requirement of the examination and this knowledge or understanding should be more thanbachelors’ degree and less than the masters’ degree.