How soon do you see warning signs of a TPK?

[aboyd]

My players were very prone to ignoring hints, going so far as to ignore a vision from a god.

And that bring me to answer the OP's question, as posed months ago. How soon do I see a TPK? Really far in advance. It turns out, I'm pretty good at doing balanced encounters in D&D 3.5 (I know, it's odd, most people think 3.5 is impossible to balance). So when the players are heading toward a TPK, I know and have unleashed warning after warning, sometimes as far ahead as 2 or 3 game days. And if they still go for it, I kill 'em all.

 

[GandalfMithrandir]

I once had a TPK from a dire rat against a third level party of four, they killed it but got bitten and died of disease as they fail their fortitude saves. otherwise it can take since the beginning of the fight to as few as two rounds, depending on the way the dice roll.