The OAS Prelims is the screening stage of the Odisha Civil Services Examination. It has two objective papers of 200 marks each, two hours apiece, with one-third of a mark deducted for every wrong answer. The marks do not count towards your final rank — they only decide who writes the Mains. Every paper below is from OPSC's own archive.
General Studies Paper I covers current events, history, geography, polity, economy, environment and general science, with a steady share of Odisha-specific questions that candidates from outside the state consistently underestimate. General Studies Paper II is the aptitude paper — comprehension, reasoning, basic numeracy and data interpretation — and is qualifying at 33%.
A note on older papers: in the 2006-07 cycle the Prelims also included an optional subject paper, a structure OPSC dropped afterwards. Those papers are not listed here because they no longer correspond to anything in the current exam.
How to use these papers
Prelims papers reward pattern-spotting more than Mains papers do. Solve the last five years under timed conditions before you touch anything older, and keep a note of which questions were Odisha-specific — that proportion is the most reliable thing you can learn from a decade of these papers.
Paper II is qualifying and often under-prepared because of it. Solving two or three tells you quickly whether you can leave it alone or need to work on speed. With negative marking at one-third, the other thing worth timing is how many questions you guess and how many of those you get right.