The Grandest Fleet’s primary emphasis is on turn based combat between two opposing forces. Players also need to control and build up coastal cities to increase income, obtain ship building capabilities, and earn victory points.
The game features a random map generator as well as numerous modern historical, fictional, and what-if naval battles from World War I to the fall of the Soviet Union.
Players can also pursue a "career" by earning points over the course of many games. These points can be used to purchase naval and civilian ranks which allow the player to bring in a personal super aircraft carrier flagship into all games. The ability of the player’s flagship depends on his or her rank.