UPSC CSE Prelims 2021 General Studies (GS) Paper was conducted on October 10, 2021, as the first stage of the UPSC Civil Services Examination (CSE). It consisted of 100 multiple-choice questions (MCQs) covering subjects like history, polity, economy, geography, environment, science & technology, and current affairs, carrying 200 marks with a 1/3rd negative marking for incorrect answers. The selection process includes Prelims, Mains, and Interview. The Prelims consists of two papers: GS Paper 1 (merit-based) and CSAT (qualifying, 33% minimum required). Candidates who clear Prelims qualify for the Mains, followed by the Personality Test (Interview).