This mode has four different characters, none of whom are featured in the single player campaign but all of whose stories are referenced in subtle ways during the single player story.
These characters battle cooperatively over the course of six unique chapters, each of which has its own story hooks and unique objects to keep things fresh.
The characters in Far Cry 3's co-op campaign are all passengers on a cruise ship that is taken by pirates when it passes by Rook Island. Their captain, simply called The Captain throughout the campaign, sells them all out to the island's pirates, who intend to sell them away to wealthy folks as slaves. As the ship is devastated, the below four characters take up arms and fight the pirates off. After this, they hunt the Captain across the island, killing hundreds if not thousands of pirates along the way.
Leonard is an ex-cop who was once on the take at his job. Now, he's a grizzled old man just looking for some peace and quiet. And sweet, sweet revenge against The Captain.
Tisha was in the United States Army, before she was set up and kicked out. Now, she uses her arms expertise to hunt down The Captain and put an end to Rook Island's slave trade.
Mikhail is a Russian hitman whose attentions were turned to The Captain when he set up his cruise ship.
Callum is a Scottish street thug, and the chef of the ship that gets sabotaged.
Far Cry 3's co-op keeps track of all of your stats across both the co-op and the adversarial multiplayer in a special profile section, where you can customize your loadouts and keep track of your level and level rewards.