The set of essential elements of the Constitution that, under the concept basic structure doctrine, Parliament cannot destroy through amendment. The courts have never fixed an exhaustive list; features are recognised case by case.
- The doctrine was laid down in Kesavananda Bharati v. State of Kerala (1973); the "basic features" are the components of that core.
- Features recognised over the years include: supremacy of the Constitution; sovereign, democratic and republican character; secularism; federalism; separation of powers; the rule of law; judicial review; free and fair elections; independence of the judiciary; the unity and integrity of the nation; the parliamentary system; harmony between Fundamental Rights and Directive Principles; and the powers of the Supreme Court under Articles 32, 136, 141 and 142, and of High Courts under Articles 226 and 227.
- The list has grown through later cases: Indira Nehru Gandhi (1975) added free and fair elections and the rule of law; Minerva Mills (1980) added the balance between Parts III and IV and limited amending power; the NJAC case (2015) reaffirmed judicial independence.
- It is illustrative, not exhaustive; the courts deliberately keep it open so that the doctrine can respond to new threats.
Statement-based questions often ask which features have been declared "basic"; knowing the commonly accepted list and that it is illustrative is high-yield.
There is no closed, official list of basic features; the items are judicially recognised over time and may expand, while ordinary lawmaking remains unaffected.
The judicially recognised, non-exhaustive core (rule of law, judicial review, secularism, federalism, free elections and more) that amendments cannot destroy.