I know this must have been done over and over, but I've built my campaign in three acts regarding the Four Winds Era in a more political setting.
Introduction: This is my take on the Era. I found that the canon one was too focused on supernatural threats and less on the political and military drama tearing the Empire asunder. The idea is that there is no right or wrong choice unless you win the throne in the end, so families are torn between the different Winds and how they represent their view of the Empire. I've set my campaign in an all-Phoenix group, but I'll set that aside so that it's useful for anyone.
Act I: A New Dawn
The stage opens on a new generation of samouraï, about 10-15 years after the Clan War. The Empire still bears the scars of total war, villages abandonned or areas unpatrolled with lack of soldiers. Threats exists in isolated locales that the regional lords haven't had the ressources to deal with, drained by the war efforts. It's important to set the stage of tensions between the families of the clans. In the Phoenix, I've made the Air and Fire Masters want to open to the Empire and expand their influence while the Water and Earth Masters wnat to close off and rebuild in peace. The Shiba try to mediate between the two factions. The idea is that if central leadership is chaotic, the players will have agency to take things in their hands and decide for themselves.
The players are part of this new generation that didn't live through the War and probably didn't leave their clan borders during their young years as the clans were licking their wounds. These upstarts might have heard legendary stories of their parents and grand-parents and covet making a name for themselves. The game begins with the gempukku of the characters in an isolated village. It might have a renowned veteran of the Clan War era as a sensei that justifies the characters being sent there. Afterwards, have them do menial samouraï tasks such as patrol, or reclaiming an abandonned village. This section is all about 'humble beginings' that players will look back to when they'll achieve greatness and build party dynamics.
I made the players travel a bit, as an excuse to encounter the Winds (not necessarily meet) so they can have a 'first impression' of them and start having an opinion of their own. Just knowing their names and 'this one is an Ishiken' can be enough so that they can start to build an idea, even on prejudice, to how their characters perceive them. I'd recommend putting some emphasis on the heir that's least likely to have the favor of the players, as to bring these more on par with the others and make for more tough choices.
This arc closes as the players receive a holding to take care of. It might be the village if the sensei dies, or anywhere 'close to the action'. At the same time Toturi I is assassinated.
Act II: Four Winds Unleashed
The first part of this act is discovery. Checking alliances and diplomacy between clans and how the race for the Throne tears everything down. Old wounds open and political ambition make for strange bedfellows. Anyone can support any wind, but I've seperated by family for the general consensus within each family. This will shake things up. Here's how I divide them (I won't go in detail as to why but you can probably justify almost anything).
- Toturi Naseru: The first official heir and politician. Doji, Matsu, Ikoma, Shosuro, Kitsuki, Isawa (Air and Fire), Daidoji
- Toturi Tsudao: Imperial Legion, bushi and intervention. Hida, Hiruma, Kuni, Bayushi, Iuchi, Kakita, Soshi, Shinjo
- Toturi Sezaru: Ishiken. Isawa (Earth and Water), Asahina, Yogo, Shiba, Togashi / Hitomi, Kitsuki, Agasha
- Kaneka: Akodo, Kitsu, Moto, Mirumoto, Yasuki, Yoritomo, Ide
The second phase of this act is the players choosing a side and trying to build a coalition with their makeshift allies. You can have a few arcs where they recruit NPCs and their retinue almost like in an videogame RPG (Suikoden II for those who know the game ^^). As the other factions do the same, conflicts spark up and you can stage a Franz Ferdinand incident (ex: A delegation of Kakita going to visit the Shinjo to plan are captured by Moto riders and held hostage; The Matsu drive out the Kitsu and Akodo that do not pledge for 'Toturi II' from their holdings and a brawl ends in the death of an important samouraï; an important figure is 'disappeared' and accusations flare up in courts).
This act should close as the players get to meet their alliance and their Wind, dodging civil war and skirmishes that erupt here and there to settle on a strategy to win the Throne.
Act III: Civil War
Here is the resolution of the factions struggling against each other. Depending on the strategy they established in the last act, pin on a board a variety of opportunities and have them decide how they allocate their ressources. Keep in mind that this is not necessarily just military action. There's plenty of room for intrigues in negociations or mediation.
- Resolve the civil war in their own clan and rally everyone to their Wind. Families fighting amongst themselves has a high drama potential.
- Implicate themselves in another clan's civil war. It's not their fight and they will lose good men fighting it; will the win be worth the sacrifice?
- Gain or maintain control of major sites. Beiden pass, the River of Gold, major ports, imperial storehouses, all of these can be fought over between the factions. Gain support of imperial legions by gaining the favor of certain officers that find themselves without orders. When everyone is fighting for the True Emperor, how much is too much?
- Use every dirty tactic to drive the players to extreme measures. Assassinate their siblings, kill off a loved one in a battle, cripple them in any way possible so that they lose compassion for their ennemies. It's important for the climax of the act.
During the course of this act, the players actions (and the other NPC factions) should drive down the choices to two Winds. The Act closes as both parties are tired and drained as they race to take the Imperial Capital to crown the new Emperor. Do they attack the legions protecting it? Depending on the other arcs and subplots you weaved inside, you should resolve them at the same time. Make them remember their early days and how they were happier in that boring, backwater village where they met at their gempukku.
The PCs don't have to 'win'; they can actually do an Intrigue where they negociate their surrender to prevent transforming the Imperial city into a battlefield and destroying the last shreads of civility that persists. If you've kicked them enough this should be a painful choice to make; after all they sacrificed, can they put that aside for the soul of the Empire? Read your players. If they are deadset to duke it out, make the fight excruciatingly destructive and vile, kill at least one of them in the final battle. If they are too quick to compromise, have the ennemy demand the seppuku of at least one of them. The idea is to have a high drama tension on the climax of the story.
The Epilogue should reflect the new empire under the new ruler.