The only time a sapper can win a battle is when it attacks a spy and sapper and a 5. It loses if it is attacked by any pieces! Keep ahold of them as long as possible b/c they are the only piece that can deactivate bombs and are the only piece other than a 5 that can kill a 5 in a battle. Once you get all of your opponents sappers adn you have a 5 left, it is ALMOST impossible to lose! This is why I trade my 5s for 4s. I like my 4s better than my 5s.