Ancient Trader is a turn-based strategy game. Players control a ship, exploring the seas in search of island ports. Sailing from port to port, players trade goods for a profit which is spent on ship upgrades. The ultimate goal of the game is to collect artifacts, special items with a price that increases over time. If the player accumulates enough artifacts, a final challenge is unlocked. Conquering this challenge requires a powerful ship, but doing so wins the player legendary treasures and the game.
Winning the game requires players to explore the sea, but the sea can be a dangerous place. Rival ships may attack the player, and deadlier still are the ancient sea monsters lurking the depths. Combat is resolved with a simple card game involving a rock-paper-scissors mechanic. Cards represent weapons and attacks with better cards available if the player spares the funds.