'Bad' switch statements are often those switching on object type (or something that could be an object type in another design). In other words hardcoding something that might be better handled by polymorphism. Other kinds of switch statements might well be OK
You will need a switch statement, but only one. When you receive the message, call a Factory object to return an object of the appropriate Message subclass (Move, Attack, etc), then call a message->doit() method to do the work.
That means if you add more message types, only the factory object has to change.
