Write a server code, it must be the same as your friend to join them! once you and your friend has joined the same server, you can begin the game! press anywhere on your map to destroy that exact spot on your friend's map! you have to guess where the ships (the red) spots are. if you hit any ships, it'll turn green on your side! then you know where to aim the next time! if any of you destroy all the opponent's ships, you win!
DON'T JOIN A SERVER THAT ALREADY HAS 2 PLAYERS!!! The game is not made to have 3 or more players at once!