The correct way to do this, is to avoid the fork() altogether, as you don't really need it.

Probably your game will incorporate an event loop at its core. This would be something along the lines of:

while (1) {

  # do each round of your game here

  if ($the_player_wants_to_exit) { &my_exit_method(); }

}

In fact, since your game involves network players, your loop most likely looks like:

while (1) {

  &get_a_message_from_a_player();

  # Do the rest of your game round processing here

  if ($the_player_wants_to_exit) { &my_exit_method(); }

}

What I would do, is to embed the processing of new players inside the same event loop. This would be something along the lines of:

while (1) {

  &get_and_process_new_player();
  &get_a_message_from_a_player();

  # Do the rest of your game round processing here

  if ($the_player_wants_to_exit) { &my_exit_method(); }

}

IMO, this will make your life easier. Take a look at IO::Socket and IO::Select, as they are of great help for what you need here.

Regards.