My sons made me smile today by reminding me of playing soldier games when I was a child. They were playing with their Lego Star Wars figures and one was being Boba Fett and the other was shooting at him. When one said he had shot Boba the other said that no he had not as he had a forcefield and then the response was that he had gone through the forcefield so that he had shot him.
This reminded me so much of playground games when I was a child. You would say you shot someone and that now he was out of the game and had to play dead but they would not want to and so as they were bad losers there was always "one last hand-grenade" which killed everyone in the game and meant you had to start playing again with everyone back in the game.
It takes children a long time to learn to fix the rules first before you play the game as if you all play by your own rules eventually there is no game at all.