Is it legal to kill someone in self-defense?

Yes, killing someone in self-defence can be legal under specific circumstances defined by law. In India, Sections 34-44 of the BNS,2023 protect the right of private defence. 

The force used must be proportionate to the threat and the danger must be immediate and imminent. Four essential conditions must exist: the defender must be free from fault, face impending peril to life, have no reasonable means of escape, and the threat must justify lethal force.

Courts examine each case's facts to determine if actions qualify as legitimate self-defence. Excessive force beyond necessity can result in prosecution under culpable homicide provisions.

The law seeks to balance self-protection with safeguards against misuse of the self-defence claim.