The only way to keep players from doing something stupid is to Just Keep Talking.
Sadly, there is no way to keep the DM from doing something stupid, although offing one of his favorite NPCs might shut him up for a couple of minutes.
The Mistakes DOOM Didn't Make
How did this game avoid all the usual stupidity that ruins remakes of classic titles?
Bethesda felt the need to jam a morality system into Fallout 3, and they blew it. Good and evil make no sense and the moral compass points sideways.
A look at the main Borderlands games. What works, what doesn't, and where the series can go from here.
The Biggest Game Ever
How did this niche racing game make a gameworld so massive, and why is that a big deal?
Games and the Fear of Death
Why killing you might be the least scary thing a game can do.