Here is the list of roles and my take on the potential for scumminess.
Cop (Whisky)
Each night you may target a player. If successful, you will get a result of town or mafia.
This can be useful for the mafia to deny the town from having, generally goes after the few picks, so we know someone early has it. Last game of this type we had the mafia take so we can't assume it is not in the hands of town, like it normally is.
Doctor (Club Soda)
Each night you may target a player. If successful, you will prevent any and all kill attempts on that player. You may NOT target yourself.
This one is a major benefit for the town, but again the mafia would love to deny this from the town, but the chance of the first two roles going to scum are highly unlikely.
Bulletproof (Vodka)
You are bulletproof. You are immune to night kills.
This is definitely a must have for a townie and more than like the first one picked. It is unlikely that the scum will pick this one, but again denial of benefit for town is good, but they will have to deny some obvious choices.
Bodyguard (Scotch)
Each night you may target a player. If successful, any and all kill attempts will be redirected to you.
NOTE: If a Bodyguard protects a Doctor and the Doctor protects the Bodyguard, the Bodyguard will be safe from attacks unless the Doctor is attacked, in which case it will die.
I doubt anyone would want this role, since it means they die instead.
Roleblocker (Rum)
Each night you may target a player. If successful, that target will not be able to use any night abilities.
This is very useful for the scum t take, since it can mean a disruption of the town. But then they might not take it so that a townie has it and looks scum.
Tracker (Irish Coffee)
Each night you may target a player. If successful, you will see all players that player targeted that night.
This is useful for the mafia also, since it means they can find active townies and then go after them. But they might have ignored this to deny the bes town roles from the town.
Jailkeeper (Lemonade)
Each night you may target a player. If successful, that target will not be able to use any night abilities.
NOTE: The roleblocker's roleblock will be given priority over the Jailkeeper's. So that means that if a Roleblocker and a Jailkeeper both target each other then the Roleblocker will not be protected by the Jailkeeper's protection, and the Jailkeeper will be notified that it has been blocked.
This is similar to roleblocker, but only weaker.
One-Shot Governor (Champagne)
Once during the game, during the day, you may PM me to stop a lynch.
This is a potential game saver if the person who has this is town.
Vengeful Lynchee (Cocktail)
If you are lynched you may, at any time during the next two phases (i.e. the next night and day), post "Kill: X" (where X was on the wagon that lynched you). That person will then die at the beginning of the next phase.
If one of the scum doe not have this as their role, then shame on them, but then again if they get scanned by the following role
Rolecop (1984 Chardonnay)
Each night you may target a player. If successful, you will see what role they have but not their alignment.
This is a good role for either side, since it allows him to know who has got what roles and who are the power roles.
Bus Driver (Ale)
Switch two players for the night (If X and Y are switched, and X is targeted by mafia, Y dies instead. Works for any ability, not just kills)
IN the hands of a mafia, this is a very dangerous role, in the hands of the town it could cause confusion. I''d mark this role down a likely for a scum to have.
Doublevoter (XXXX Larger)
Your vote counts as two in the lynch.
Not very useful early on, but later on it can control the lynch, so this is mightily useful for the mafia, but could have not been taken.
Tiebreaker (XXX Larger)
Your vote can break ties in the lynch.
Unlikely to be taken. But more useful in the towns hand.