If I consent to something, the other person can never be punished for it.

Consent only protects against liability for the harm involved (under Sections 87-89). If the act is a crime for other reasons, Section 91 makes clear that consent does not excuse it.

Section 91 creates a new offence.

Section 91 doesn't define any new crime. It simply limits how far the consent-based exceptions in Sections 87, 88, and 89 can be used as a defense.

Indian Penal Code, 1860

Section 91

repealed

Exclusion of acts which are offences independently of harm cause

The exceptions in sections 87, 88 and 89 do not extend to acts which are offences independently of any harm which they may cause, or be intended to cause, or be known to be likely to cause, to the person giving the consent, or on whose behalf the consent is given.§

Why this exists

Sections 87–89 of the IPC create exceptions to criminal liability when a person consents to risk of harm (like in sports or medical treatment) or when an act is done in good faith for someone's benefit (like a doctor treating a patient). Section 91 was added to prevent these consent-based defenses from being misused to excuse acts that are independently criminal—such as illegal abortion or duelling—regardless of whether harm was caused. It draws a line: consent can excuse harm, but it cannot legalize an inherently unlawful act.

Common misconceptions

Myth: If I consent to something, the other person can never be punished for it.
Fact: Consent only protects against liability for the harm involved (under Sections 87-89). If the act is a crime for other reasons, Section 91 makes clear that consent does not excuse it.
Myth: Section 91 creates a new offence.
Fact: Section 91 doesn't define any new crime. It simply limits how far the consent-based exceptions in Sections 87, 88, and 89 can be used as a defense.