Revolving Door Villains
There’s a running joke that in high-magic fantasy games, death is naught but a revolving door and the party cleric is the doorman. I haven’t played much 4e myself, but I’ve heard many of the epic-level abilities start out “Once per day, when you die…” If there’s a bigger way to hang the “death doesn’t matter” out for everyone to see, I haven’t found it yet.
What about villains, though? Unless everyone is playing a pulp-style adventure, having the villain inexplicably escape every time he’s encountered can seem contrived and simple GM-fiat, but can the revolving door be used as a plot device to present the players with a unique challenge?