Running mood altering devices - Advice?

[Abe.ebA]

I'm working up some ideas for a potential campaign to run this fall and a large part of the overall plot will revolve around some cursed items. I'm planning to borrow an opening I read in another thread here that really caught my attention: the characters all find themselves in a room holding loaded weapons (crossbows, I think, in my case) surrounded by strangers (the other PCs and a couple of NPCs) and a few bodies on the floor. The twist here will be that everyone has, in addition to the crossbows and the clothes on their back, an old coin set with a little chip of stone in the center. The stones will vary in color and each has different powers. Offense, defense, strength, dexterity, etc. The PCs will be unaware of the coins nature and may not even be initially aware that they have them or that the rest of the party does.

Eventually the coins manifest their abilities in one way or another and, beginning at that point, slowly alter their hosts' minds. In addition to a particular theme of abilities, the coins have a certain trait or emotion tied to them. Anger, paranoia, greed, corruption, etc. The longer someone carries the coin and the more they use its powers (or allow it to manifest them on their behalf), the more control the coin has over its host's mind.

My question here is how to run this. Should I tell the PCs straight out (one-on-one, that is) after their coin initially manifests its abilities what it's doing and let them roleplay it, or should I slowly clue them in by 'forcing' emotions on them? In the latter case I think I'd just pass notes with messages along the lines of, "As you sit near the campfire, you suddenly have a feeling of being watched. Looking around, you realize that the rest of the party is staring at you. They all look away and pretend otherwise immediately, but it's obvious that something is up." for Paranoia, or "A slight fellow with a bad haircut and a bit of a droop to his features bumps into you as he turns away from the bar, sloshing his drink on your shirt. An unexpected rage boils up within you and you have your sword half out of its sheath before the anger vanishes as rapidly as it came, leaving you feeling empty and flushed." for Anger.

I can't decide which is more 'railroad-y'. I don't want to tell the players how to play their characters, but I also dislike dictating what their characters should feel, even if it's due to a magical compulsion.

So what would you do?

 

[Frostmarrow]

Just take your time and listen to the players. Once they've shown you the way they play their characters you tell them about the true nature of the coins. Give each a trait that they already have. That way they get to chose how to play their respective characters in a natural way but once they learn about the coins they only need to exaggerate what they have already been doing. Be flexible about traits and emotions, though. Pick ones that suit them - not ones you would rather have. I.e. make it up as you go along.

 

[Agent Oracle]

Give it to the habitual roleplayer first. Use an arcane and odd word to describe the mood, and let them work with it. For instance, I was running a D&D game where prolonged exposure to a particular BBEG caused sanity loss. (THe players didn't know they had SAN as their "extra"... I did) Well, the players got to make several saving throws as the BBEG Monologued, and one of them (a bard, ultraroleplayer) failed every time. So, when she ran out of sanity, I had the BBEG "poof" away. then I told the player: "you are "gibbering" for the next... thirty-one hours."

She looked at me, and asked what "gibbering" meant.

I told her: "Think of the prisoner, long forgotten yet still alive, left only to his own mind and the horrors that it contains. Think of the patients in a victorian asylum, their eyes more white than pupil, contained among filth and decay. Think of the beast which dwells within the human psyche that can be named, but never described. THAT is the sensation of gibbering."

She turned white, and for the rest of the full session, her bard was helpless (the other characters had to carry her twitching, sobbing, chuckling, babbling character out of the temple) She did a great job expressing what i was trying to convey, and when other players followed suit, they likewise acted as she had... spazzing out into twitchy, delusional states. one went so far as to attack the party, but they subdued him (thankfully)