In the competitive card game Eridanos, your goal is to sink your opponent's ships by choosing the best combination of attacks at just the right moment. In more detail, players take control of a fleet of ships, engaging in head-to-head combat. Each round, four cards are played into the foray face down, after which players take turns attacking and withdrawing with their vessels until one side has surrendered. Each card has a specific strength or weakness, winning or losing only to the exact cards listed on it. To win, you need to enter your opponent's mind to determine which cards they have and outmaneuver them to victory.