Running plots and betrayals

Contrary to the more linear (or direct) Dungeon Crawls, running a game with betrayal and plots takes a different yet similar approach, but can be very rewarding and as challenging or more challenging than the best dungeon crawl.

First, to run a good plots-heavy adventure, one needs an appropriate setting. Usually, but not always that's a city, or a court, a fair, or a trade meeting - a place where different factions, groups and individuals gather and don't kill each other openly.

Next, one needs the "movers and shakers" - the NPCs, individuals and groups that are behind the plotting - and their goals, means, motivations and relationship to each other. Those can be simple or complex.

"The Wesir wants to become caliph.
He has a few personal servants, among them an assassin he magically bound to his service, his personal fortune, and knows a number of dark secrets about the nobles of the realm to blackmail them.
He wants to become caliph since the new caliph, young and spoiled, will ruin the realm in his opinion, and cause great suffering.
The caliph dislikes him since he was the trusted right hand of the father of the caliph, but trusts him to have the interests of the realm at heart. The nobility is split between the older families who like the wesir, and the syophantic newcomers who curry favor with the caliph, and dislike the wesir's policies. The population has been enjoying the "bread and circusses" policy of the new caliph and remembers the wesir as a strict, and miserly governor."

"The Caliph wants to get rid of his Wesir.
He can't just dismiss him, since that would cause trouble with the older nobility, and he doesn't want to kill the wesir since that might show a weakness ("he can't find the murder/protect his trusted allies, he is weak"), or taint his reputation ("He got the Wesir killed, how ungrateful. He is a tyrant"). He does control the treasury though, and can "buy" the population and the nobility that supports him by granting favors and privileges, and providing "bread and circusses", until the Wesir is weakened, and his own position more secure, so the wesir can "retire".
The wesir considers him a spoiled caliph, and ruining the realm. The nobility is split between syccophants supporting him, and older families supporting the wesir, who stands for the policies of the former caliph. The population loves the caliph. The new religious leader supports the caliph.

The new religious leader wants the wesir gone and the caliph isolated.
He has access to his churches' priests, as well as a secret cult of assassins, and the support from his patron, a devil.
He wants the wesir gone and the caliph under his iinfluence so his church can take over the realm after a devil possesses the caliph or the caliph has become a follower of the devil.
THe new religion is not yet accepted by the population, but tolerated, although the lower classes and some of the new nobility embrace it.

Once that is laid out, the DM can think of possible actions and reactions the different groups and individuals would take, and how the PCs would figure into it. Getting the PCs involved is the most important part, since how they get involved defines the adventure. They can get hired to investigate a seemingly minor or major event by any party or even an outsider. They can arrive as trade envoy escorts, and end up framed for the murder of the envoy, having to prove their innocence. They could try to get a favor from the caliph, and start to meddle in politics. They could be part of the old or new nobility, or tied to old religion, or get fooled into doing some dirty deeds by a henchman of any party. Part of this is also picking some scenes that may happen when the PCs are present, and actions that are tried by the different groups.

Once this is cleared, the "chaff" is picked - the plots and scenes not related to the main plots, which add flavor, red herrings, and side quests as the PCs try to get to the core of the adventure.
The lieing servant they follow around after having seen her in the night checking doors may not be lieing for a plotter, but to protect her daughter who's having an affair with a soldier and prepares to elope before the caliph notices her and wants her in his harem.
The new noble bribing people is just trying to get a favor for his home region. The old noble looking for an assassin is not after the wesir or the caliph, but wants to avenge the death of his son a few years ago at the hand of a duellist bravo, and just happened to talk to the guild that also does the wesir's dirty deeds.

Once that is done you have a weave of NPCs, relations, possible scenes and actions. Now comes the main part, running it.
Some may want to run it like a dungeon, with scenes linked by actions instead of rooms linked by doors. I prefer a more flexible approach by focusing on the PCs, and running them into scenes depending on what they do and where they are, mixing "chaff" and "core" scenes as I deem best.
If the PCs arrive in the city after a Dungeon Crawl and carouse in seedy taverns I might have an agent of the Wesir approach them, looking for some discrete people for a discrete task - or fools to frame for an assassination. Or the mentioned noble wants to hire them to avenge his son. Or they just happen upon the daughter of the servant, running from the palace fearing for her virtue. Or they save a friend of the caliph from robbers - actually disgusied assassins - and are brought to the court as heroes, causing all plotters to revise their plans and trying to take advantage of their presence, and themselves.
From how the PCs handle themselves, I then decide how the rest of the world reacts, and create new scenes, if needed.

If all works out you'll have multiple sessions filled with action and plots, linked together by true and false clues, ending with a climax when the big plot is exposed and foiled, and possibly some open ends left dangling, ready to be taken up or expanded later - or continued straight on.

It's less episodic, and there will be less downtime between "adventures" until the location of the plotting is left by the PCs, or all plots have been solved, which is unlikely, so it may not be to the taste of every group.

But for those who like this sort of games, it's much more rewarding than more linear, more straightforward plots.