When my group plays, we adventure about under the basic assumption that the GM has scaled all the challenges to our characters’ power level. Some encounters might be easy, some might be really challenging, but they all should be winnable. Should an encounter prove is impossible, we hope our GM would indicate that in some obvious way before a TPK. This hope is likely a dangerous assumption.
In my latest game our DM surprised us by throwing a black dragon into the encounter. Our characters took it in stride and started attacking it. Even after we loosed daily after daily on it and it wasn’t bloodied, like heroes, we persevered despite all rationality. After all, she wouldn’t have put a dragon into the encounter unless we could defeat it… right? Thankfully we were able to subdue our foe, but it came close. In hindsight there was no good in-game reason to stay and fight. But our Standard Operating Procedure is: we haven’t died yet so we must be invincible.
The only way this attitude makes sense is in the meta-game: we rely on the DM to move the plot forward and make encounters winnable. I think the role-playing purists out there would be unkind to me for this behavior, and I wouldn’t disagree. As role-players we should be playing the role of our characters and try to think as they would. This failure of imagination isn’t the worst part! The bigger issue is that we’re relying on convention for our character’s survival, there’s nothing to prevent the DM from seriously outmatching us. The only thing stopping her is fear of whining players or slowing down the rest of the game as the survivors proceed over-cautiously through the rest of the dungeon.
So… against all my instincts and advice, I guess we’ll keep doing it until it bites us in the ass. GMs if you’re reading… if your party does this, give them one or two over-powered encounters with an easy out so I learn your serious without dire consequences. And if they still don’t listen, then go in for the kill >:-).