Nice plot idea reminiscent of Philip K Dick's "A Scanner Darkly".
It would make an ideal start to a campaign but I can see it could be tricky to pull off in an already ongoing game.
To make the latter work, have the 'Nicco' character wake up one morning murder weapon in his possession (preferably in his hand) with the entire neighbourhood abuzz with the news of the horrfic murders nearby. He has no recollection of anything happening in the night naturally. To make it even more interesting, make it the character that is the most disliked in the party.
And of course the murdered family were all friends to the PCs, perhaps a recurring helpful NPC from the past to make it more personal for everyone.
This way the characters will have a good incentive to investigate the crime, the 'Nicco' character will have enough incentive to hide his role from the others until he has figured out what has happened and you can have further complications to add to your campaign: perhaps Nicco has been framed, perhaps Nicco's weapon is cursed and similar crimes will happen in the future, perhaps Nicco has been geased or otherwise coerced without his knowledge. Then you have other ends to throw in, like if Nicco isn't behind it, who is...? Go to Comment
I think I would use this as a first adventure type thing. Pick one of my players that I can trust to pull it off, and give him the history of Nicco and let him play the part. Moral dilemma of telling his friends (in character and out of character), keeping it from them, lie, throw them off the trail, hide some evidence.
Everybody will know something is going on, or do they, but will they figure it out? A good one where any conversations about the game would be in characters since "Nicco" has to keep up his story and the others don't have a clue to what is going on exactly. Sounds like a lot of fun. Go to Comment
I realy like the idea and all, however, I am afraid it is next to impossible to create the situation for this event to occur.
Even though there is a lot of players who like to stick around a certain city or point in a campaign world, many also like to travel. If I look at the characters I like to play, they would never make good guardspeople, not even special brigade guardspeople.
Also I feel that you put the PC who is playing Nicco in a impossible situation. He either gets hanged for killing the people or he gets hanged for not finding the killer... (or he can flee the city)
Personaly I would set this up with Nicco being a NPC, that way, I would be much easier to pull of I feel. Go to Comment
If your characters want to move around, then this is a fine story to begin with...assuming they don't give up their man or accuse an innocent, they will most likely sneak away. This could lead to a good fugitive background to link them together.
Or, just have the man get them fired. Then they are free to seek employment that will take them out of the city. Go to Comment
Oddly enough I have a player who is portraying an assassin at night and a student by day. He has joined a guild that could easily ask him to do jobs and help the local militia. This fits well, but I agree that it is a very situational plot and has to be worked real hard into a setting. Go to Comment