VoidFactions is the perfect solution for grouping players into factions. It is a great choice both for Serious and Non-Serious RP servers. Everything is customizable, optimized, and configurable through an in-game config panel. (faction/gang/organization/party/ranking/whitelist system)
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Brick's Gangs - Printers, Territories, Associations, In-Game Config + More
Brick's Gangs is a gang system designed to allow players to group up with each other and create gangs, the system includes role management and creation, gang storage/inventory, upgrades, achievements, associations, leaderboards, territories, levelling, a gang balance and an admin panel.