Prelims consists of 2 papers on the same day:

PAPER I — General Studies (200 marks, 100 questions, 2 hours)
  History               15-20 questions
  Geography             15-20 questions
  Polity & Governance   15-20 questions
  Economy               15-20 questions
  Environment & Ecology 10-15 questions
  Science & Technology  10-12 questions
  Current Affairs       15-20 questions

PAPER II — CSAT (200 marks, 80 questions, 2 hours)
  Comprehension
  Logical Reasoning & Analytical Ability
  Decision Making
  General Mental Ability
  Basic Numeracy (Class X level)
  Data Interpretation

⚠️ IMPORTANT: Paper II is QUALIFYING (33 marks = 26.67/200)
Only Paper I marks count for Prelims cutoff
Marking: +2 for correct, -0.67 for wrong (1/3 negative)

Indus Valley Civilisation (3300–1300 BCE):
  Sites: Mohenjo-daro, Harappa, Lothal, Dholavira, Rakhigarhi
  Features: Town planning, drainage, weights & measures
  Decline theories: Climate change, Aryan invasion (debated), floods

Vedic Period:
  Rig Vedic: Pastoral, no caste hierarchy, tribal polity
  Later Vedic: Agriculture dominant, varna system crystallising
  Upanishads: Philosophical texts, basis of Vedanta

Buddhism & Jainism (6th century BCE):
  Gautama Buddha: 4 Noble Truths, 8-Fold Path, Anatman, Nirvana
  Mahavira: 24th Tirthankara, Ahimsa, Satya, Asteya, Brahmacharya, Aparigraha
  Difference: Buddhism rejects extreme asceticism, Jainism demands it

Mauryan Empire (322–185 BCE):
  Chandragupta: Founded empire, defeated Seleucus, Kautilya's Arthashastra
  Ashoka: Dhamma, edicts (rock/pillar), spread Buddhism after Kalinga war
  Decline: Fragmentation after Ashoka's death

Delhi Sultanate (1206–1526):
  Slave Dynasty → Khilji → Tughlaq → Sayyid → Lodi
  Key: Alauddin Khilji's market reforms, Ibn Battuta's accounts
  Tughlaq: Revenue reforms, Doab taxation, moving capital to Daulatabad

Vijayanagara Empire (1336–1646):
  Founded by Harihara & Bukka, capital Hampi
  Krishnadeva Raya: Peak, Telugu literature, Amuktamalyada

Mughal Empire (1526–1857):
  Babur: First Battle of Panipat 1526 (Babur vs Ibrahim Lodi)
  Akbar: Din-i-Ilahi, Sulh-i-Kul, Mansabdari, Navratnas
  Aurangzeb: Jizya reimposed, Deccan wars, empire's overextension
  Revenue: Todar Mal's zabti system, Ain-i-Akbari records

1857 Revolt: First War of Independence / Sepoy Mutiny
  Causes: Enfield rifle cartridges, annexation policies, resentment
  Centres: Meerut, Delhi (Bahadur Shah Zafar), Kanpur (Nana Sahib),
           Lucknow (Begum Hazrat Mahal), Jhansi (Rani Laxmibai)

Indian National Congress (1885):
  AO Hume founded, Dadabhai Naoroji (first president), Surat Split 1907
  Moderates: Gopal Krishna Gokhale, Dadabhai Naoroji, Pherozeshah Mehta
  Extremists: Bal Gangadhar Tilak, Bipin Chandra Pal, Lala Lajpat Rai

Gandhian Era:
  Champaran 1917 → Kheda 1918 → Khilafat+NCM 1920 → CDM 1930 → QIM 1942
  Dandi March: 12 March – 6 April 1930, 241 miles, salt satyagraha
  Quit India 1942: "Do or Die", mass imprisonment, underground resistance

Partition & Independence:
  Mountbatten Plan June 1947, Indian Independence Act July 1947
  Partition: 14-15 August 1947, Pakistan (West + East)
  Sardar Patel: Integration of 562 princely states

Indian Physiography (5 divisions):
1. Himalayan Mountains
   - Trans-Himalaya: Karakoram, Ladakh, Zaskar ranges
   - Greater Himalaya (Himadri): avg 6000m, perpetual snow
   - Lesser Himalaya (Himachal): Pir Panjal, Mussoorie, Nag Tibba
   - Outer Himalaya (Siwalik): foothills, tarai, bhabar

2. Northern Plains: Formed by Indus, Ganga, Brahmaputra alluvium
   Bhangar (old alluvium) vs Khadar (new, fertile)

3. Peninsular Plateau: Deccan Trap, Eastern & Western Ghats
   Highest peak: Anamudi (2695m) in Western Ghats

4. Coastal Plains: Western (narrow, straight) vs Eastern (wide, deltaic)

5. Islands: Andaman & Nicobar (Bay of Bengal), Lakshadweep (Arabian Sea)

Monsoon mechanism:
  June: Southwest monsoon hits Kerala, advances northeast
  October: Northeast monsoon brings rain to Tamil Nadu
  ITCZ shifts north in summer → pressure differential → winds blow from sea to land

Major Topics:
- Plate tectonics: Ring of Fire, fold mountains, earthquakes
- Ocean currents: warm vs cold, effect on climate
- Climate types: Koppen classification (Tropical, Dry, Temperate, Cold, Polar)
- Resources: minerals, oil reserves, rare earth metals

Strategic locations UPSC loves:
- Strait of Hormuz: 20% world's oil
- Strait of Malacca: busiest shipping lane
- Suez Canal: connects Mediterranean to Red Sea
- Panama Canal: Atlantic to Pacific

Constitution:
  Adopted: 26 Nov 1949 | Implemented: 26 Jan 1950
  Borrowed from: UK (Parliamentary system), USA (Fundamental Rights, judicial review),
  Ireland (DPSPs), Canada (Federal with strong centre), Australia (Concurrent List)

Fundamental Rights (Part III, Articles 12-35):
  Article 14: Equality before law
  Article 19: Six freedoms (speech, assembly, movement, profession, residence)
  Article 21: Right to life and personal liberty
  Article 21A: Right to education (added by 86th Amendment 2002)
  Article 32: Right to constitutional remedies (Dr Ambedkar: "Heart and soul")

Directive Principles (Part IV, Articles 36-51):
  Non-justiciable but fundamental in governance
  Socialistic: Articles 38, 39, 41, 42, 43, 45, 46, 47
  Gandhian: 40, 43, 43B, 46, 47, 48
  Liberal: 44, 45, 48A, 49, 50, 51

Important Articles frequently asked:
  Article 356: President's Rule
  Article 370: J&K special status (abrogated 2019)
  Article 44: Uniform Civil Code
  Article 51A: Fundamental Duties (added 42nd Amendment)
  Schedule VII: Union List, State List, Concurrent List

Key Concepts:
  GDP: Market value of all final goods and services
  GNP = GDP + Net Factor Income from Abroad
  NNP = GNP - Depreciation
  Per capita income = National income / Population

Sectors:
  Primary: Agriculture, mining, fishing
  Secondary: Manufacturing, construction
  Tertiary: Services (IT, banking, trade)

RBI Functions: Monetary policy, currency issue, banker's bank, foreign exchange
SEBI: Securities regulator (1992)
NABARD: Agricultural credit
SIDBI: Small Industries Development Bank

Important Economic Bodies:
  NITI Aayog (replaced Planning Commission 2015)
  Finance Commission: Article 280, fiscal federalism
  Economic Survey: Annual, Chief Economic Adviser prepares

Current affairs topics always asked:
  GDP growth rate, inflation (CPI vs WPI), fiscal deficit,
  current account deficit, foreign exchange reserves

Biodiversity hotspots in India (4 of 36 global):
  1. Eastern Himalayas
  2. Western Ghats + Sri Lanka
  3. Indo-Burma region
  4. Sundaland (Nicobar Islands part)

Protected Areas:
  Wildlife Sanctuary → National Park → Tiger Reserve → Biosphere Reserve
  India has: 106 NPs, 567 WLS, 53 Tiger Reserves, 18 Biosphere Reserves

Ramsar Sites (Wetlands of International Importance):
  India has 75+ Ramsar sites (as of 2023)
  Important: Chilika Lake, Keoladeo, Loktak, Wular, Sundarbans

Climate Agreements:
  Kyoto Protocol: 1997, binding targets for developed nations
  Paris Agreement: 2015, all countries, NDCs, 1.5°C target
  India's NDC: 45% emissions intensity reduction by 2030 (vs 2005)

Recommended Books:
  History:     Spectrum Modern India, NCERT 11-12, Bipin Chandra
  Geography:   NCERT 11-12, Majid Husain's Indian Geography
  Polity:      M Laxmikanth (Indian Polity) — most important book
  Economy:     Ramesh Singh (Indian Economy), Economic Survey
  Environment: NCERT 12 Biology, ShankarIAS Environment
  Current:     The Hindu daily, PIB, Yojana, Kurukshetra

Monthly schedule:
  Day 1-15: Static syllabus (1 subject per day rotation)
  Day 16-25: Current affairs compilation
  Day 26-30: Revision + 2 full mock tests

Mock test strategy:
  Minimum 30 full-length mocks before exam
  Analyze wrong answers — note the concept, not just answer
  Aim: 85+ correct with 100-105 attempts (not all 100)
  Cutoff typically: GEN ~98, OBC ~95, SC ~85, ST ~80 (out of 200)