A required attack action is present BUT then says just right of the attack icon "If your groundshiver is level 5 or higher:". Does that mean you can only engage if your gourndshiver is level 5 or higher? Otherwise just skip the card? It seems confusing that you would skip the action if you are worse at detecting the enemy, but maybe this is just a way to make the game harder only at more experienced levels (i.e. higher groundshiver levels)?