3D Armada is a 3D video game adaptation of the classic Battleship home game. Either a human player can play against the computer or human players can compete against each other via TCP/IP network play. Each player gets a 10x10 grid of water squares that are occupied by a fleet of 10 ships-- there is one ship that occupies 4 squares and then there are 2 3-square ships, 3 2-square ships, and 4 1-square ships. Naturally, players can not see the other player's ships. A player makes random strikes against the opponent's nautical positions and is informed when one of the strikes hits something. This is used to estimate where more of a particular ship may lie.

After one player manages to sink the other player's entire fleet, the game treats the participants to a replay of the entire battle, but with both fleets in plain view.