So today in our show: "The Players Ate my Baby", we're gonna talk about dealing with cheaters. Every one of us cheated at least once in his/her gaming career. It can be fudging dice, and it can be rerolling 1s when we're not supposed to. I'm not gonna talk about GM's dice fudging, mainly because sometimes it is important to fudge a little, but on the other spectrum, when players do that.
"Rob, roll reflex against fireball."
Rob rolls a 1. - "11, made it?"
We all had it happen to us, we all encountered that, and all of us tried different ways to deal with this, be it ignoring it or killing the characters. I, personally, believe in a different method: "We GMs can always cheat better than the players." So, according to this method, if the players can cheat, so can we, and when we'll cheat, it's gonna hurt them really bad.
It doesn't matter if the cheat will be extra damage, extra life, or something much more sinister, as long as the lesson is understood: "Don't cheat, or we'll hurt you so much you'll pray the character was dead." I, for example, when one of my players "fudged" his die from a 1 to 20, "fudged" my 4 dice from 1 to 20. When that particular character lost his arm (I don't kill many characters), he pleaded for a second chance. Needless to say, he didn't ever cheat again...
Now, don't get me wrong, I don't believe in killing characters, or making game un-fun. It's not my style. But, when a player cheats, it hurts the fun of everyone else on the table, and if it won't be punished, it will return (usually, at least).