Differences between Section 34 and Section 149 IPC

Section 34- Acts done by several persons in furtherance of common intention.- When a criminal act is done by several persons in furtherance of the common intention of all, each of such persons is liable for that act in the same manner as if it were done by him alone.

Section 149-If an offence is committed by any member of an unlawful assembly in prosecution of the common object of that assembly, or such as the members or that assembly knew to be likely to be committed in prosecution of that object, every person who, at the time of the committing of that offence, is a member of the same assembly, is guilty of that offence.

Both Offences talk about crime by group of people. Such that if a crime is done by 2 or more people but less than 5 then section 149 is not applicable whereas section 34 is applicable on those offences.

Section 149 deals with the 5 or more people as that would account for unlawful assembly here section 34 is not applicable.

Section 34 talks about common intention whereas section 149 talks about common object such as the common object has a wider scope. Common intention is if two or more person commits any crime with the same intention and under a prearranged plan, But in common object  it is not necessary that there should be a prior concert in the sense of a meeting of the members of the unlawful assembly, the common object may form on spur of the moment; it is enough if it is adopted by all the members and is shared by all of them.

In section 34 Participation of the people in crime is an important aspect, even standing people who indirectly help in commissioning of crime are also prosecuted.

But in Section 149 mere membership of the group of an unlawful assembly is sufficient enough for prosecution.

Section 34 is a substantive evidence and other sections like 302 murder has to be clubbed with it.

Section 149 is a constructive crime in itself.