Far Cry 3 offers a lengthy single-player campaign as well as two major multiplayer modes—competitive and cooperative. While the competitive mode is split between a variety of modes, the cooperative mode is made up of a 4-player campaign that consists of several large maps, not unlike Valve's Left 4 Dead–featuring pirates and mercenaries instead of zombies.
Today, VG247's Sam Clay has released the final video diary for Far Cry 3 to talk about the game's multiplayer Battlecry and decoder systems. With Battlecry, players can essentially "shout" a buff at nearby friends in the cooperative campaign. It's not unlike the Barbarian's shouts in Diablo 2 and Diablo 3, or a Bard's song in any D&D game or MMORPG with an equivalent class. The Battlecry system encourages players to stick closely together and work as a team.
The other topic that the video covers is the game's decoder system, which enables players to unlock new mods for their items after placing a collectible item in the decoder. These items are attained from completing missions in multiplayer.
If you're wondering how the game works, the video serves a comprehensive tutorial for these systems.