The pattern of the UPSC Civil Services Mains exam consists of a written examination followed by an interview. The written exam includes nine papers, comprising compulsory papers such as Essay, General Studies (four papers), and optional subjects chosen by the candidate. Each paper is of a descriptive format, allowing candidates to showcase their knowledge and analytical abilities. The total marks in the written examination are combined with the interview marks to ascertain the final merit list. This multi-faceted evaluation ensures a comprehensive assessment of candidates' capabilities.