I had an idea for an adventure mechanic and wanted to know if anyone had some thoughts on it. The setup is simple: we start a new campaign with the characters created in advance. Each player receives a character sheet, along with some background information for their character. However, whereas most of the characters' description includes something along the lines of "You started work for Firewall... blah blah blah," one character's sheet states "You work for and have infiltrated a Firewall cell. Your orders are ." Of course, none of the other players in the group know that one of them is a spy (at least, not in the beginning). The more I think about this, the more my head starts to spin when I think about the number of ways that you could make this operate, based on shifting all kinds of variables in the campaign. A few ideas: 1. The spy's directive is to secure for their employer a copy of the data that Firewall is trying to gather (whether it's intel on an exsolar colony or the DNA of some new bio-plague is irrelevant). The job of the player in this case is to get their hands on the data (which will require different amounts of work depending on the skillset of the player in the group--why should the mercenary hold onto this when we have someone highly skilled at data encryption and transmissions?) and either make their own copy of the data or send it off to their employer. The player will want to have some quiet side conversation with the GM before gameplay starts to work out the mechanics of how he'll try to swap out the info. 2. Whatever Firewall is out to collect, it's the job of the spy to destroy. In this case, the spy will have to arrange for some "alone time" with the thing they're trying to collect, and either destroy it or swap it with a fake version (which Firewall either will or won't recognize as junk). Again, you'll want to have a quick sitdown with your GM so they understand what you're really doing when you say you are "analyzing the encryption signature" (or whatever other passphrase the player concocts). 3. This is really the dream scenario for me, though it will be a little difficult to manage. The players will be directed to either retrieve some data from somewhere or perhaps assist some group with defense against attack. Once again, the spy's employer has an interest in things going badly and/or keeping certain secrets from being uncovered (I'm thinking a trip to some still-running facility somewhere on Earth might work well for this). At some point, one of the NPCs believes that they have been compromised in some way (maybe they intercepted a transmission from your team that shouldn't have been made, or perhaps the defenses themselves fail in some spectacular way) and starts accusing the PCs (or maybe some small group of them including the spy) of colluding with an outside force. I've been thinking it over, and at this point I think it would behoove the GM to disclose the fact that, yes, one of the PCs is a spy (will want to make clear to the spy's player ahead of time that this may happen). To me, it seems that outside of such direct confirmation from the GM, players would look at the NPC making the accusations as being paranoid (or themselves a spy). At this point, the PCs will have to try and figure out who the spy is and what to do (you might also want to make the spy's player aware of the fact that he might want to think about an escape plan). 4. One last idea: the spy's assignment is to infiltrate the Firewall group and act as a sleeper agent. Their only orders are to report back to their employers at the end of each mission and to wait for further instructions. In this last scenario, the GM can build a much larger story around this fact, hopefully crafting a story that makes the spy start to question their allegiance to their original employer (either they bond strongly enough with their team to overwhelm whatever loyalty they had to their employer, they are somehow betrayed by that employer, or perhaps simply by working for Firewall they realize the dark stuff that's out there and they realize who the good guys really are). At some point, they will want to confess to their teammates and see how things go from there. A few aspects of this kind of adventure to keep in mind (at least, that I've thought of): First: What's in it for the spy? The first three scenarios I listed above could be done in a single gaming session. Some players might be willing to play a "disposable" character for a single session (I feel like some people could get a real kick out of getting to play a spy and would be willing to do it just for the fun of it). Otherwise, you might want to promise them a few extra character creation points for the next character that they create to offset whatever gains they would have otherwise made with their character. Second: How will the other players react? The fourth scenario I listed above involves a lot more time and energy, and players are going to be pretty upset if the spy doesn't make that change of heart but instead hamstrings them when it comes to the big climactic battle, wrecking weeks of solid gameplay. Ultimately, I think that the long-term-spy option is really about good storytelling, and have a great "reveal" for the other players (which may make a number of them suddenly understand all sorts of odd behavior from their teammate during gameplay). Hopefully, most players will appreciate it and not feel any kind of actual betrayal. Also, from here on out as a GM, you're going to have to open every new adventure with "There are no PC spies in this campaign" (though, of course, that still leaves open the possibility of NPC spies :-D ). Third: How good is your spy player? This is ultimately the trickiest part of the idea, since obviously you can't have someone by a spy if they don't have a good poker face. The whole thing is largely predicated on planning and communication between the spy's player and the GM, so if you're going to do this long-term, you're going to want to talk to the player ahead of time. Of course, if the player isn't up for it, you've just spilled the beans about the secret plan and will have to manage that as well. The one big piece of advice that I'd give the spy player is this: be patient. The main job of infiltrating another group is to look as much as possible like you're a part of that group. Don't let them think that they need to be constantly "checking in" with their real employer or otherwise doing strange things all the time. For the most part, being the spy will mean being a regular PC as part of the team--they really shouldn't have to make many overt actions outside of their normal gaming actions (which could not only confuse them, but also arouse suspicion from the other players). Well, anyway, that's what I've got. Really looking forward to other people's thoughts on this.