Another excellent article by Chris Perkins. This week he tackles encounter balance, and specifically the question of whether a DM should throw over (or under) leveled encounters at his players. For most of 4E's life I've adhered to the encounter-building guidelines in the DMG, and I'm starting to question the wisdom of that. In my TOR game Grimwine's player has consistently refused to run away from combat (incidentally he's the only one who has almost died twice), and it's been bringing to mind the philosophy of "oh, the DM wouldn't put it here if we couldn't beat it." Ultimately, I think that breaks immersion because the characters would be completely unaware of any encounter-balancing mechanics, and should behave with their own survival in mind, without constantly being the most powerful presences around. Obviously with "all balanced encounters" being the norm a DM needs to be explicit up front about his intentions to populate the world with all manner of threats, some of which the PC's cannot reasonably expect to defeat. It's also important that the DM always keep in mind alternative "outs," whether those be escape routes or motivations for the over-leveled threats that makes the PCs more valuable alive (captured) than dead.
Another interesting anecdote is that while all of the published 4E stuff is balanced for the party's level, there have been several combats in the published TOR adventures that assume the players will run away.
*That's what she said.