- 5 Town Desperados (as a day action, you can shoot a player; if they're scum, they die, otherwise you die)
- 3 Mafia Desperados (identical to town Desperados; thus they either kill a buddy or themself)
- No lynching/nightkills, and the game lasts only one phase; all kills are made via the Desperado ability.
- Town win by killing all the Mafia.
- Mafia win if two townies die (i.e. the game uses the Black Flag mechanic).
Scum are never going to use their Desperado ability on town (they'd be better off claiming scum and forcing someone else to kill them, because at least that way they simply die, rather than dying and confirming a townie in the process). However, it's important to the setup that they have the option to shoot each other in an attempt to look town.
I'm not sure how wise it is to actually run this (although knowing me, I'll probably run it anyway), because it requires discipline by the players; if players are going to shoot without discussion, they can end up losing very quickly. (That said, impulsive players are quite possibly less likely to use Desperado shots than Day Vigliante shots, considering the potential downside.)
As a side note, I've been wanting to make a "zoraster-style" setup for a while. This one wasn't explicitly intended as one, but it seems to have ended up in the same sort of space.
This almost certainly also works at higher player counts (seeing as it's technically a Bad Idea variant, it probably even scales up into the hundreds without much difficulty), but analysing the Micro-sized version was hard enough, so I'm not sure offhand exactly how many players you'd need. (It's probably rather easier to analyse if you just
assume
the strategy I gave above is optimal, though, rather than trying to prove
it's optimal like I was.)