UPSC Prelims negative marking: formula, risk and attempt strategy

UPSC deducts one-third of the marks assigned to a question for a wrong answer and gives no penalty for a blank. The useful strategy is not a universal attempt count; it is a calibrated rule based on your evidence and accuracy.

Reviewed: 29 July 2026Reading time: 9 minutesBased on UPSC papers and rules

GS Paper I formula

Net score = (2 × correct answers) − (2/3 × wrong answers). Unanswered questions add zero. If more than one option is marked, UPSC treats it as a wrong answer.

The official rule

UPSC’s examination FAQ states that the Preliminary Examination has two compulsory papers of 200 marks each, both objective and two hours long. General Studies Paper II is qualifying at 33%. For a wrong answer, one-third of that question’s marks is deducted; a blank has no penalty.

Primary sources used

Paper structure and penalty rules are checked against UPSC material. Practice explanations and strategy recommendations are UPSC Genie editorial guidance, not instructions issued by UPSC.

UPSC previous question papers · UPSC question-paper archive · UPSC examination FAQ

GS Paper I score examples

Correct	Wrong	Blank	Approximate net score
50	20	30	100 − 13.33 = 86.67
55	25	20	110 − 16.67 = 93.33
60	30	10	120 − 20 = 100

These are arithmetic examples, not cut-off predictions. Cut-offs vary by year, category and the actual paper.

What elimination changes mathematically

Situation	Random-choice expected value	Practical meaning
4 live options	Approximately zero	A blind guess has no mathematical edge before real-world errors
3 live options	About +0.22 marks	One reliable elimination may justify an attempt for some candidates
2 live options	About +0.67 marks	Two reliable eliminations create a stronger case to attempt

Expected value is a long-run average, not a guarantee on one paper. An elimination based on a false assumption is not reliable elimination. Track your own medium- and low-confidence accuracy before adopting an aggressive rule.

A two-pass attempt method

First pass: high evidence

Answer direct knowledge questions and items where the elimination is clear. Mark uncertain items for review without forcing a decision.

Second pass: calibrated risk

Revisit marked questions. Attempt when your personal accuracy for that confidence band supports it; leave questions that remain blind.

Protect OMR time

Use the booklet and OMR procedure required in your current admit-card instructions. Do not let late guesses create transfer errors.

Build your personal attempt rule

For five full PYQ or mock papers, label every attempt high, medium or low confidence.
Calculate accuracy and net contribution for each band.
Keep the bands that add marks; tighten the rule for bands that consistently lose marks.
Repeat the calibration under time, not only in relaxed practice.
Review whether the failure was knowledge, elimination or OMR/time management.

Practise with real negative marking

Take a timed UPSC Prelims mock or a year-wise PYQ set, then compare net score with your confidence and attempt decisions.

Start scored practice

Frequently asked questions

What is the negative marking in UPSC Prelims GS Paper I?

For each wrong answer, one-third of the marks assigned to that question is deducted. In a 100-question, 200-mark GS Paper I, that is about 0.67 marks per wrong answer.

Is there a penalty for an unanswered question?

No. UPSC states that a blank question carries no penalty.

How many questions should I attempt in UPSC Prelims?

There is no safe universal number. Use your mock and PYQ accuracy by confidence level to decide which questions are worth attempting.

Does eliminating one option make guessing profitable?

Mathematically, a truly random choice among three remaining options has a positive expected score under the one-third penalty. In practice, elimination quality is rarely perfectly random, so validate the rule with your own results.

Continue the Prelims PYQ cluster

PYQ practice hubStart with the complete practice workflow and live-bank coverage.Year-wise PYQsUse recent papers as timed simulations and older papers as a pattern library.How to analyse PYQsTurn every right and wrong option into a revision decision.How many years?Choose a realistic first pass, second pass and exam-mode set.

Questions are drawn from UPSC Civil Services Preliminary Examination papers. Explanations, categorisation and strategy are editorial learning aids. Report a doubtful answer through the corrections process.