Sea Dogs is reminiscent of Bethesda's classic RPG, Daggerfall, in which players were free to choose any course of action they wished in a limitless and unbounded game. You can give your allegiance to one of three countries (France, Spain, England) or choose to serve only yourself as a swashbuckling pirate. At any time you can change your allegiances by changing sides, giving up pirating to join the cause of a country, or leaving your country to fight for another. Regardless of your actions, you always have the ability to choose another course through a number of means, such as bribery.

Players begin the game with a small ship and some general guidance as to what they might do next. Towns serve as focal points in the game, allowing you to repair, re-supply, and upgrade your ship, pick up new crewmembers, look for work, or simply listen to rumors. Sea Dogs provides a series of quests and missions that will keep you headed toward an overall final objective, or you can choose to follow your own path. Sail the seas looking for ships to fight to test your battle skills or make your fortune as a trader.

Through wealth or combat, you can obtain additional ships and place them under your command. You decide which NPCs to hire as captains and have them work with you to complete missions, such as attacking and capturing other ships or forts.

Sea Dogs allows you to experience this battle first hand as you fight for England, Spain, France, or yourself in a struggle to control the islands. You develop your character from humble beginnings and rise to control all of the islands for your country or yourself. Hire a staff to help manage your ship and crewman to sail it and fight for you. Build your wealth and reputation and use it to acquire bigger ships, better crewman, and even add other ships to your fleet. You can choose to fight, trade, accept quests, seek out rumors, or do anything you like. The choices in Sea Dogs are endless, and so is the adventure.