XIX century, times of the Civil War in the United States of America. Union troops manage to block Confederates' access to strategic ports. Thus, they cut off their rivals from many trading options. The opposing side decides to seek help from pirates in retaliation, and with their help it wants to violate the Union's domination at sea. Captain Abraham "Nightingale" Grey - a desperate smuggler with a daring temper, decides to take advantage of the conflict.
Swashbucklers: Blue vs. Grey allows players to play the role of the owner of a pirate boat, who is waiting for a great career in the Caribbean Sea. The gameplay consists mainly of free swimming between ports, completing tasks and clashing with other ships. The user may accept any orders that allow him to support one of the parties (the Union or the Confederation) or to remain neutral. You can modify the main character's ship, which allows you to turn it into an impregnable fortress or a fast ship perfect for boarding.
Captain Nightingale can disembark to accept quests and engage in saber and firearm duels. In Swashbucklers: Blue vs. Grey, RPG elements appear - the protagonist gains experience, and with it new skills. Depending on his preferences, he can become an expert in fencing or navigation.