Underboss or Vice-Leader or Second In Command is the second highest rank in a gang just right behind the leader. The Underboss can make decisions but has to inform the boss to gain his/her approval. The Underboss is often related to the Boss. Carl Johnson was a Vice-Leader of the Grove Street Families while his brother Sean Johnson is the leader. During a gang war an Underboss is mostly targeted by other rival gangs and so is the Don and his Consigliere. The reason they are mostly targeted is because they are the leading members of a gang will prevent the gang of getting a new leader due to the Underboss being next in line to being the Leader.

Notable Underbosses