Percentage roles are extremely unpopular due to incorporating a large and uncontrollable element of luck to a game, potentially negating any skill the player with the role may have. In extreme cases percent-based roles may be seen as an excuse for the moderator to toy with the players. It is recommended in most cases that percentage roles not be used at all, as many players associate it with bastard modding.
Well, if it's unpopular it's unpopular, and maybe there's nothing I can do about that. But the justifications given don't seem very compelling to me.
- large and uncontrollable element of luck:Well, they add an element of luck, sure. Whether it's large depends on how it's done. I'd say it usually just replaces one kind of luck with another: it's bad luck for a mafioso to be targeted by a cop or tracker on the first night, but using a percentage cop or tracker can mitigate that, at the expense of exposing that role to the possibility of their own bad luck. As for uncontrollable, that leads into my next point.
- potentially negating any skill the player with the role may have:This is only true if you think it's impossible to reason with uncertain information -- but this is the whole point of Mafia! Any newbie can make himself useful as a cop, but a 50% or even 75% cop has tothinkabout the investigation results and continue paying attention to the discussion to see if they make sense. This offers more opportunity for skilled players to outperform unskilled ones.
- may be seen as an excuse for the moderator to toy with the players:I assume this means the moderator might PM a player with (e.g.) "50% <Role>" but actually just report failure every time, or whenever it's funny. This isn't a problem with the percentage mechanic, it's a problem with bad moderating.
If this is just a matter of players having a learned association "percentage => bastard mod", rather than the mechanic itself being bad, that can probably be mitigated by restricting it to open games, or at least games where all roles are 100% self-aware.
What do you all think? Am I missing a major point here, or do I have some hope of running a game with percentages without pissing everyone off?