If I have a player playing a Wookie who decides to wrestle with a Rancor the Rancor will have a furry snack. He might cough up a hairball later on, but if a player character decides to do something like that and is warned about the consequences and thinks its all a joke (I've had a player in the past who thought that in a game of D&D once... he was mad when his character died to the dragon because he felt that a DM wouldn't put in something that the player's couldn't kill) then he deserves what he gets.
However, I prefer it if the players comes up with a really cool story reason for why their character ends up leaving the game through whatever means the player feels is best. I've had a character die a fun, glorious death in a previous game a while ago to save the rest of the party and to allow me the chance to play something different.
I'm also a dice-fall-where-they-fall girl and game master... I always roll in front of players and I don't hold punches. This is why I love games like EotE and Fate and Cortex+ games because these games are designed with all rolls in public view.