Running an All-Scorpion campaign can potentially be one of the most rewarding (if difficult) games for most L5R GMs. Given the reputation of the Clan, the characters involved in such a campaign have to be strongly aligned to a single purpose beyond simple survival.
Scorpion campaigns make an interesting mirror to a Lion Clan one. Where the Lion are always overshadowed by their Duty and Honor, the Scorpion campaign is always overshadowed by the issues of Duty and Loyalty.
Personal conflict is one best explored in the Scorpion. Bayushi Shoju, by far one of their most popular characters epitomized this when he had to make the difficult choice of killing the Emperor in an attempt to save the Empire. While being a Scorpion often means that you’re not quite as restricted by Bushido as other Clans, it doesn’t mean that you’re free from it.
Loyalty is a tricky thing, and several other plot hooks work neatly into it. From an internal coup or civil war, to hidden agendas and conspiracies like the Gozoku, the Scorpion are often victims of their own penchant for secrets.
Clandestine operations are another good way to play the Scorpion Clan, a group sent to various Clans as a diplomatic delegation, for example, could also be an investigative team / assassination outfit. This forces the players to play two roles, the public and the secret face of their characters. Having a Shosuro acting troupe here is actually a neat idea.
That said, the Scorpion Clan’s specialty in duplicity and disregarding Bushido is always a strong hook. What’s important is that the GM is able to present the Scorpion as more than just the stereotype. Personal desires, ambitions and emotional issues are powerful hooks for a Scorpion game, and will do a lot to present the Clan as being made of people.