I have been mulling over the use of character deaths in a game based on telling a group saga, dealing with the repercussions of a character and player out of the action for a considerable chunk of time. Why do authors kill major characters, and why would a game master kill off a player character? Sure games are about the luck of the dice, but there is something to be said about having characters live through to the final chapter.
Characters that have been around a while have time and energy invested in them, and that time and energy should be rewarded by at least wrapping up the loose ends of their story. This isn't to say a character cannot die in the game, but it should be meaningful and generally after they have dealt with their major character issues. Would Lord of the Rings have had the same impact if right before Samwise and Frodo made it to the mountain they were killed by orcs, and two new characters, whom no one had ever heard of for the last 9 hours or 900 pages, finished the task for them? And just where did these two new characters come from, or even know the importance and location or the event they were just thrust in to by being the next character sheet on the pile?
I do understand that players can, and often do, make some easy mistakes, like counting hit points before deciding to stand in front of a dragon with teeth larger than they are. In situations where the player decides to take the worst possible course of action, gently suggest there might be alternatives, if they don't act in the path of self preservation then just let the dice fall where they may. Indeed the warrior my have a thousand hit points, but to the dragon they are just more nourishing calories. If the player acted smartly, and was the only one felled in the battle, perhaps just making them knocked unconscious with a bit of healing required as it isn't really a free out, so that the player doesn't miss game time to build a new character because the numbers didn't roll right once or twice.
For TaleMix I am instituting a rule, er guideline really, that unless it is a total party wipe out, the fallen player characters are merely incapacitated. If even one player remains king of the hill in a fight, there is a good chance they can recover their team, there is always the chance of player or character personality that would just as easily loot friend as they would foe, and go about their business. A good way to alienate a table full of friends though.