As an ST, I have some rules/assumptions for conflict, which I tend to carry over in those rare instances I get a chance to play. These are all lumped together from running Shadowrun, Werewolf, Mage, Wraith, Trinity, Aberrant, and various other games.

1. I've never killed a PC.

Actually, I lie. I slaughtered the PC's in the Vampire tabletop game I ran (the one that put me off Vampire forevermore), but to be blunt they were mindless fuckheads. I killed them for that, and because I wanted to get out of the game, and as revenge. This is the only time I have killed a PC, even in Kult and Call of Cthulhu. Because for me, killing a PC means presenting a situation in which a PC's death is unquestionably going to happen. Too much like railroading for me.

2. PC's kill themselves.

Let me explain. PC deaths, to me, come about from PC's doing something stupid, or being in the wrong place at the wrong time. Frequently, that wrong place is in the path of a bullet that is heading through them. But it is the player's fault for putting himself in that situation. It doesn't matter if it's something like charging the guy with the Panther assault cannon, or saying 'I moon Pax'. If they are captured by a group in Kult that uses them as a ritual sacrifice, then that is their fault. I never plan situations that will lead to PC death. If they're in the wrong place, however, the player put the character there and should deal with the results.

3. PC's don't have to die.

Practically every game has methods to allow a PC not to die. WW has Dodge and Soak, and the various powers which can be used to augment these (try shooting a laser at someone with Photokinesis 3). If the player does not take advantage of these factors (not dodging, not wearing body armour when they know they'll end up in a fire-fight), that's the player's fault. Not my fault as an ST. Players should realise that there is a chance of death in any hostile encounter and plan accordingly.

4. Death happens.

Especially in games set in darker realities than our own. Shadowrun, Kult, and the World of Darkness are all dark games. Death is just a part of that. Last I looked, despite some of the corebook, Changeling is just a part of the World of Darkness. Death may be chimerical or real, but removing it as something that could possibly happen cheapens the whole point of the game. If there's no real risk of a character being unable to go on, then nothing is gained by succeeding.

5. Planning for death.

Don't. Having 'backup PCs' in case of the death of a character is not good planning. The PC's are inevitably less thought out, not because of history, but because of story integration. Saying 'Oh, I died. Here's my new character' dicks the ST about. If you don't know when the character is going to be inserted into the game, you cannot craft an adequate back story. If the world has changed drastically over the past 5 sessions, then your PC dies, bringing in a character that has not had any experience with the world changing destroys the continuity.

Character death shouldn't happen in minor scuffles, I'll agree. Drop a group of muggers at a Shadowrun team and watch the muggers get used for target practice. But on the other hand, we can't take death out of the game, or it removes a lot of the 'dark' from settings like the World of Darkness.