(When) is it OK to TPK?

Total Party Kill. Game Over. The Bad Guys Win.

I don't know how I feel about a TPK in RPGs, and I suspect I'm not alone in that. This month's RPG Blog Carnival at Rising Phoenix is all about When The Bad Guys Win, so I'm trying to get my feelings down on what happens when the Good Guys lose.

Character death is part of the stakes of a lot of our games.  It keeps us on our toes as players. Hitpoints or harm are often one of the resources players have to manage.  There can be a great deal of drama - and satisfaction - in epic battles against overwhelming odds, even if we lose.

In sandbox / West Marches style games - or any games where the difficulty of encounters is set based on what is fictionally appropriate rather than balanced against PC levels - it can be OK for the party to be in over their heads.  If they go into The Forest Of Death And Blood underprepared, against the advice of the DM (or their NPCs), then getting wiped out should be expected. Right?

Image (cc) jaymethunt

But just as a character dying can derail a plot thread, a TPK can derail a whole campaign narrative.  I want to build stories around the PCs, so what happens if all of those PCs suddenly die?

• Can we salvage the campaign by rolling up a "rescue team" to go in after the dead PCs and complete the mission?
• Can we roll new characters, with new goals, and start over in the same world and time but going in a different direction? Or working for the other side?
• Can we fast forward a year, a generation, a century - to a world changed by the PCs' failure and start a fresh party, and a fresh campaign?

Are these viable solutions?  Do we just start a new (different) game?  Some common solutions to a TPK can, IMO, be really bad for the game:

• Fudging dice rolls to keep players alive.  If you're fudging rolls, DM, why are you even rolling?
• Avoiding throwing any potentially fatal encounters at the party. This can remove a lot of the fun for some players.
• Friendly NPCs save the day / reanimate the PCs. If it's fictionally appropriate then fine. You want to signpost how much of a threat the enemy is by letting the PCs get beaten so they can come back stronger and win in the end? Great. Otherwise, how often are you going to save their bacon? Every time?
• The PCs are captured, not killed. Again: if it works in the fiction, or if you intended them to be overwhelmed and captured as part of the plot - fine.  But it's not going to work every time.

TPKs suck in a lot of ways, but if we take away the risk are we really just railroading?  Should we avoid them, embrace them, manage them, or ignore them?