A Judas is originally a pro-town role, but when it should die (either by elimination or other kill) it stays alive and converts to the Mafia's side instead. The Town is told nothing except that the elimination failed.
Both roles are named after people from the New Testament of the Bible. The name 'Judas' derives from Judas Iscariot while 'Saulus' comes from the German for Saul of Tarsus a.k.a. Paul the Apostle. In Werewolf Online, this role is called "Cursed" and only turns into a werewolf if killed by wolves (if eliminated, shot, torched by the arsonist, etc., it dies).
The Judas role in practice tends to lead to ugly situations. However, that hasn't stopped mods from trying to make it work:
- The Judas aspect is commonly Hidden from the player until they convert. (Since it's already a bastard role, why not?)
- In the interest of balance, the Judas may not be told who the rest of the Mafia are upon conversion.
- Judas may also appear in games with Saulus, thus muddying what kind of role caused the elimination to stop.
- In Greater Idea Mafia, the Judas converts only on elimination. If nightkilled, it dies normally.
Use and Power
Judas is actually not that bad for balance if it gets eliminated immediately upon conversion; in games with a single Night-kill it evens out to a single miselimination - which is what the Judas would have been if it were eliminated as a Vanilla Townie anyway. The major concern plaguing Judas is the alignment change (see Category:Alignment-Changing roles for more information).
If you do not want it known that a Judas is in the game, consider having extended Twilights so as to give the illusion of the existence of a Governor.
If the Judas is self-aware and converts when eliminated, they can claim for an automatic win if only one Mafioso is alive. Either the Mafioso dies in which case the Judas wins with the Town, or the Judas eliminates themselves at 2:1 to win with the Mafia. (However, if this Judas does not also convert when nightkilled, they still need to watch out for Vig shots.)