Have you ever been, or used, an adversary player?
I mean someone who is not the GM controlling an NPC or NPCs in your world, acting against the PCs? Either on a one-session basis ("Here, run these orcs!") or long term ("Here, run this major NPC for me.")
Here are two war stories of my experiences doing this.
The one time I got to do it, my friend R~ needed some help with his Dark Ages-era Vampire game. His players had assembled a small army of militia, soldiers, and artillery plus some ghouls and their own vampire PCs and sent them down into the Balkans to do battle with an NPC's force.
He asked me to run said NPCs force in the big battle that would ensure. He wanted to pose a real challenge to them. One of the players was an old-school wargamer, and R~ is not (although he's a hell of a gamer in general).
So I took the force roster and the battlefield and set to work. I didn't really know much about the PC's powers - but neither did the NPC. I did know how to use what I had. Masked siege gun batteries set up to blow up any vampire foolish enough to take the bait of some exposed high ground, cavalry screens and reserves, veteran troops backing militia types forced into fight-or-die positions, etc. I set up the best defense I could with the forces I had.
When I arrived, the players were a bit dismayed that I was actually running the bad guys. So they gave it their all, and really pulled out the stops to win the fight. Knowing it was me running the clever bad guy helped - they suspected traps, deduced some of my likely tactics, and leveraged their powers against them. "My" forces fought hard, but they were over-matched and the PCs took them very seriously. It was a bloody rout but "my" guys did some damage they might not have otherwise.
The Email Adversary
In my previous fantasy game, I ran a "limited sandbox." The main campaign area was the map of the Known Worlds from the old D&D module X1 The Isle of Dread. I stocked it with major NPCs and plot threads to trip over and lots of things to do. My players went to it and set a lot of things rolling. So much so, that I had trouble deciding what some NPCs would do. It was too easy for the players to try to play me, and decide what I might do and plan off of that, and too hard for me to come up with really interesting twists.
Some people would create a table and roll dice in this situation.
I emailed my friends and asked them to play NPCs.
I asked a number of people to run NPCs for me. The old-school wargamer I mentioned above, a few online friends, one fellow freelancer, and one of my former gamers. I divided up the NPCs between them, one each. For each NPCs we did a quick back-and-forth email conversation to decide jointly on a personality for the NPC that matched my expectations as the GM and theirs based on what they knew of the NPC.
Then I'd occasionally email them for decisions about things based on the NPC.
I chose major NPCs in my game. Not the really mover-and-shaker bad guys, but rather NPCs who could be allies, patrons, or adversaries for the PCs. This way I could have both the over-arching plot (the PCs vs. the evil wizard they inadvertently aided in his nefarious goal) and have independent NPCs doing their own thing and reacting in surprising but consistent ways.
Some of these didn't work out - a few of the NPCs ended up being rather marginal. The PCs didn't choose to interact with them. So I never needed to call on these guys.
But for one, Prince Vladimir Morfailov, one of the immortal wizard-prince rulers of Glantri, it worked out amazingly.
Prince Morfailov was run by Chad Underkoffler, then a fellow SJG freelancer, now an independent game writer.
We worked out the NPCs mannerisms and traits, based on his brief, indirect interaction history with the PCs. We worked out some salient details of his domain, and his interactions with other princes. I ended up with a very interesting NPC who wasn't quite how I'd have made him. I had to shoot down some ideas as too different from the campaign's basis, but others fit in so well I can't now remember if they were my idea or his.
The Prince was first encountered, indirectly, when he visited a series of nasty curses on a Glantrian citizen - who hired the PCs to defend him from the Prince's punishments.
But then the PCs needed a job, and one of the people they contacted was that Prince. Hey, they knew he knew how good they were at their job.
He accepted and hired them.
While working for him, some interesting stuff happened. Once they were sent off to help on of the Prince's allies win a border war. They did, but they also spied on the NPC's secret experiments, and their thief-type clobbered their boss's ally's head demon-worshipping priest and stole a major artifact-level book from him. Basically, he robbed their boss's ally while the rest of the group was out winning the war.
I emailed Chad and, role-playing Morfailov's top henchmen in charge of the PCs, told him, wondering how Morfailov would take this. Me, I had no idea, but I figured he'd be pissed.
Instead, he was delighted. He brought them back, rewarded them for their actions, and chastised his ally for taking so long to "return" the book, "MY book," to him. Further, he promoted the PCs up in the ranks a bit faster and ordered their supervisor to hand down the rewards. This was really fun, because I ran their supervisor (Chief Thug Boris) as being fair but only mildly tolerant of their antics. Now he had to reward them. It was pretty easy to play a chagrined supervisor in that case. I can't believe he sent them to back his ally to the hilt and then rewarded them for backstabbing the guy's chief religious officer. Importantly, I would never have had the NPC do that. But he did.
It was a lot of fun for me and for my players, because we all knew that no one at the table could really predict Morfailov's actions. Maybe he'd be happy with their performance. Maybe not. He was extremely powerful, hideously rich, and somewhat capricious. He could be amused by their performance in a task and dump wealth upon them, or quixotically disappointed and give them punishment duty. He might hand out a powerful magical item as a reward or a silly trinket that addressed some real or imagined need for the PCs ("For you, here is a ring that will keep your clothes clean. And for you, a set of hideously powerful unique throwing spears to rain death upon your foes!") We never knew what it would be.
And if he happened to make decisions that helped or hurt the PCs fight the Main Bad Guy, well, it wasn't me tipping the scales either way - because they knew the Prince didn't have all of the inside knowledge that I did.
We kept this up for a long time, until after the PCs did a full game-year's duty working for him in return for some service in return. After that, I'd still email Chad occasionally when they interacted with Morfailov, up until towards the end of the campaign.
I haven't done this yet, this campaign. It's not that kind of game, but if it becomes so, I might do this again.
Next post, some lessons I think I learned from these experiences.