Massclaim

It is common now in Theme Games for the Roles to be named based on some theme, such as characters from homestarrunner.com, trees, or fictional space colonists. Because of this, the Town may be able to theoretically guess which Role Claims are real and which are false based on how well they fit into the theme, not on the player's actual actions during the game. Reasons for 'catching' someone in a false claim range from obvious reasons like "It's Zarquon, not Zarquar" to more esoteric ones like "Would Rincewind really be a good guy?". This has given rise to a strategy called the Mass Roleclaim, in which everyone reveals their role and then those who are less plausible get lynched. This is considered by many to be a corruption of the game and a Breaking Strategy to boot.

As a result, many Game Moderators have added roles to their games that stretch plausibility in order to thwart such tactics. The players in Texas Mafia (Mini Game #30) got a nasty surprise when they discovered that there really was a pirate, and that it really was ProTown!

Unthemed Open Setup games may also be vulnerable to Mass Roleclaim when too many players have unique roles. Since the number of each role is known, by having everyone claim their role, the town can swiftly narrow down which players must be lying. This can be far more valuable than whatever abilities the roles actually possess, so that it's not a deterrent that Mass Roleclaim allows Mafia to immediately learn everyone's identity.