And of course the 3e DMG does recommend that ca 5% of encounters be EL 5+ over party level and the PCs should run away!
If there's a fate worse than death for some players, it's having to flee. Of course, IME, those players that refuse to flee, that believe ona fundamental level that the DM wouldn't include an encounter they were'nt supposed to be able to win, are the ones most likely to be exceptionally upset if a character dies.