"That will be 25,000 gp in diamonds, please."

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?

In our previous campaign, I introduced a group of villains who were for all intents and purposes immortal, able to re-form their bodies if they were physically destroyed.  While this could easily become 'cheezey' or unfair, the rationale fit with the background of the game in this case.  This changed the nature of the characters' interactions with the villains (who had no fear of death) and had some interesting effects on the story.

• The players were able to directly confront their enemies face-to-face from the start, they didn't have to crawl through layers of an organization to get to them.  Their enemy was quickly personified for them and they were able to attach their animosity to a single small group of entities instead of successive levels of middle management.
• Because the enemies couldn't re-form instantly, the characters were able to hinder their enemies through direct interaction.  The characters could vanquish a foe, costing them valuable time and possibly resources in the process, but the foe could come back for revenge eventually.
• I didn't have to worry about making the enemies miraculously escape, since in effect they couldn't be destroyed permanently.  No bodies hidden from view as they fall or magic just-in-time teleportations - if they died they died.

There's definitely a danger in this sort of thing of the whole setup being too heavy handed. If it's not explained sufficiently or just hand-waved, then revolving door villains can be just as frustrating to your players as the miraculous escapees.  But if you can create a plausible explanation that fits in your game world and doesn't break immersion, it can by an interesting plot device to exploit.

A gamemaster should watch his players' reactions and shouldn't let this go on too long - at some point the players should obtain the ability to defeat their opponents permanently, otherwise the game will get quickly become repetitive and predictable.  When the enemies realize the characters have obtained a way around their insurance policy, they'll suddenly have to approach them in a new way, as they have to learn how to think like mortals again.  Maybe some will defect to the characters' side, or others will start to seek non-direct means of interacting with the party.  No matter how things change, the gamemaster has the opportunity to take the relationships that the players have built with their enemies and twist it in interesting ways.

There's also the issue of the omnipotent adversary.  Inexperienced gamemasters can fall into the trap of giving their adversaries full knowledge of the party's actions even if said adversary lacked a sufficient means to gain such information (by spying, scrying, etc).  But again you can run into the trap of the cookie-cutter with things like the traditional wizard with a crystal ball.

When my turn to gamemaster came around in our current game, I decided to use a little trick to get the party invested in one of their adversaries as well as explain why the characters had been oiled in their recent attempts to accomplish their goal.  Unbeknownst to the players, I made one of their characters the adversary.

Occasionally we've found ways to write our own characters out of the story temporarily when it comes to our turn at the head of the table.  Early in the campaign, one player helped another get their character out the session before the second player took over as gamemaster.  There was an elderly woman, we believe some sort of wizard,  who offered to show him information regarding a conflict he had set up in his background.  The character agreed, promising to catch up to the party when he returned.

The character showed up a few sessions later but soon thereafter the party suffered a number of setbacks.  When I took over as gamemaster, I continued the setbacks, including the theft of the party's MacGuffin.  Given how exacting the theft, the party knew that it has to be an inside job, but they were all alone and there were no NPCs around who could have sold them out. Suspicions started mounting and tensions built, but no accusations were made aloud just yet.

The party tracked the thieves to a ruined temple and as they prepared to launch their surprise attack, I handed the following note to the player whose character (Saxon) had just got back from his leave of absence.

Note: Through the Looking Glass
You may not read this aloud.

The last thing you remember clearly is stepping through the portal with the old woman that night between Perrin and Kroson.  After that everything was dark for a time, then you became vaguely aware of your surroundings, though through a haze of pain.

You’re not sure how long everything lasted, but you remember having things done to you.  Experimentation.  Operation.  You were never conscious enough to know exactly what was going on but you were always aware of the pain.  Especially when they carved out your eye and did... something.

Unsurprisingly, this should be confusing to you – it’s not something that your character knew about.  That’s because the character you are currently playing is not Saxon.  Who or what he is is irrelevant but right now you are not playing Saxon.

When the battle below is joined, you have specific instructions:

• Draw Plot Points until you have 10.  You may spend these freely and you will get back however many you have right now +4 when you regain control of your original character.
• Turn on the party.  I would suggest starting weaving your flame wind spell “to help”, then after it’s up surprising folks by hitting a party member.  I would ask you to put a big hit on Marcus first (we’re 100% he can take it ), but from there do whatever you want to cause problems for the party.
• Add a d4 to all Channeling rolls.

Your actual character is one of the people bound and hooded up front.  Every round I will be rolling Saxon’s dice to escape his bonds.  When he is free you may assume control of him and I will take faux-Saxon.

As expected, hilarity ensued.

Not the "malicious gamemaster likes to mess with players' characters" or the "evil gamemaster likes to watch his players get screwed" kind of evils either.  I had approached the player about the disfigurement previously and he agreed to it, though he didn't know the context at the time.  And the players weren't mad at my "hijacking" a character at all.  In fact it made all of their sabotages of their previous few goals make perfect sense.  There was no resentment towards a player for turning on the party, because the player never actually did until I made him (and only for one fight).

I think it's a testament to my group's maturity and the trust that exists between each player/gm that this went as smoothly as it did, and I wouldn't recommend it to a gamemaster unless he was sure that it would go over positively with his group.  Without trust players can feel cheated because the one thing they control in the world - their character - just got pulled out from under them.

If your group is willing to accept this sort of plot twisting, it's not hard to set up.  It works best when there was an opportunity for the switch to be done that the player put their own character in.  In this case it was Saxon's side trek off camera with the old woman (who turned out to be one of the campaign's antagonists).

After that it's just a matter of observing the party's dynamics and having the character do things when he gets the chance to work against the party and not telling the player.  Things like (in our case) taking the MacGuffins out of their storage place while he was supposed to be on watch and delivering them to an NPC that had been tracking the party.

There is the danger of resetting a character too much, though.  In our case we added two players to the group since Saxon's replacement, meaning he (Saxon, not the player) was away from the party for four sessions.  So the relationships that he had formed with the new characters had to be re-formed.  This wasn't an issue for our group but it's something that a gamemaster has to be cautious of.  If you reveal an impostor after dozens of sessions, that's a lot for the player to try and rewind in his head and keep straight.

I've gotten a lot of positive feedback from my group regarding Saxon's replacement and betrayal.  But like any good gamemastering advice, this is going to boil down to knowing your group.  A role-playing group is built around trust between the players, and the last thing a gamemaster needs to do is ruin inter-player trust.  But if that trust exists, twists like this can be very enjoyable for everyone involved.

One of the issues I struggle with the most is story pacing.  Story pacing is different than game pacing.  Game pacing - maintaining the flow of action and involvement of the players - is key to running a successful game but that's not where my problem lies.  I have a harder time revealing story elements and "clues" throughout the game in a way that keeps the players interested in finding out more but doesn't just simply give the story away.

Our rotating gamemaster game was set up with a simple rule - the only facts that you control as the gamemaster are the ones that you introduce in-game to the players.  And when your time in the chair is over, you pass everything off to the next gamemaster to do whatever they want with.  They may take what you created in a completely different direction than you did, but that's their prerogative as the gamemaster.  Likewise, you're free to do whatever you want when it's your turn in the chair.

With the overall story out of my control, I was pretty much free to do whatever I wanted.  I didn't have to worry too much about spreading out clues and story elements, because I would only be running two sessions before the next player took their turn as gamemaster.

On the flip side, I did get to benefit from the threads of story that were dropped before.  No gamemaster fully explained in-game everything that happened in their time behind the screen, which meant there were a number of loose ends and unresolved questions that had been building up.  I decided to take the opportunity to wrap many of them up in a "season finale" style, answering as many questions as I could in such a way to re-frame the task that the characters have been assigned.

It was simultaneously challenging and refreshing not having to parse out the story over the course of the previous eight sessions, being able to just weave a story from what strands were handed to me, and then wash my hands by passing the game off to the next gamemaster.

After having to set up the story arc in my previous games on my own, this week's job felt a lot easier.  With less to worry about, I was less stressed and was able to just enjoy the experience more.  I'm not saying that I'm ready to start up a new campaign of my own any time soon but I've definitely started to feel comfortable in the gamemaster's chair again.