Expanding on the last post, I’ll be providing an example of the Decision Tree campaign model today. No player characters were harmed in the production of this post, I promise.
First off, the players: we’ll say we’re working from Starfinder for these purposes, using the default setting. One person brings a shirren (insect-folk) soldier with the bounty hunter theme to the table; the second brings a human technomancer with the mercenary theme; and the third bring a lashunta solarian with the outlaw theme. All together, the sorts you’d expect to find working together for their own benefit.
So to prepare, the first spot on the decision tree is their starting point; in this case, they’ll be starting off down in the Spike of Absalom Station, where they’ve been tracking a mark down for a couple of weeks. They’re running low on credits and really need to score this bounty payoff to make ends meet. We start them off in media res with them outside the place where the bounty has holed up, as far as they know.
So far this is just generic stuff, but this is where the Tree begins to come into it. This adventure will have them break in and discover the mark fled just ahead of them, but left all his stuff behind in his haste to get away. That stuff includes the hooks that lead to future branches. The mark has left behind his personal datapad, a stolen drive with encrypted files on it, and a deed to a junker of a ship.
His personal datapad has a hook on it: his personal correspondence with someone who simply gets tagged as M, with the information he’s provided and the payments he’s gotten for it all tidily listed. Following this hook will lead the players onto a path of conflict with the evolution of the Red Mantis Assassins, who are looking to disrupt the Pact Worlds and make an opening for the Swarm, which they believe to be the manifestation of Achaekek.
The encrypted data contains a pair of hooks; one is on a corporation apparently associated with the ancient House of Thrune, and concerns something called the Nessian Dynamo, with hints that it can produce a tremendous amount of power, even more than the Starstone at Absalom Station’s heart. Following that hook gives the group a plot that diverges a few adventures farther down: when they learn it produces power by literally burning the chaos and goodness in souls, leaving what’s left to go straight to Hell, they’ll get to pick if they want to try to destroy the knowledge of it, or claim it for themselves (the themes suggest they might be amoral enough to take the latter, after all.)
The second hook in the encrypted data is there if they want to play up the mercenary angle of their characters; it’s a file indicating that anyone capable of decrypting it is welcome to come compete to win a contract from a wealthy sponsor (a cult-corporation dedicated to Norgorber) to perform corporate espionage, outright theft, and the occasional bounty for them. This, too, splits fairly soon after, with an option to take the contract and essentially slide down an amoral slope, or to see if there’s a line they won’t cross for money – which will make an enemy of their employers and get an assassin squad sent after them.
The final hook in the hideout is the deed to the junker ship; it’s laid out in a way that makes it easy to transfer ownership, essentially making whoever has the deed the ship’s owner. The mark has had it but not been doing anything with it, and is oblivious to the travel logs on board. The logs detail several planets visited by the ship that don’t make any sense, and if the players pursue that they get to explore uncharted systems that seem to be torn from the Outer Planes into the Drift and from there into the Material Plane. They can chart them and sell the navigational data for a fair chunk, contract with an exploration corp (or the Starfinder Society) to explore them, or they can chase the mystery of what brought these systems into the material universe in the first place, because no Drift drive should be capable of such a feat.
Last, there’s the mark himself. The players may want to keep chasing him, and they should absolutely be allowed to do so. Let them bag him, collect the bounty, and get contacted by an organization of bounty hunters, offering to let them join. From there, they can chase bounties across the galaxy, with a general plotline that crosses the Red Mantis, the Cult of Norgorber, and Thrune Corp, collecting bounties both for them and on their members.
No matter what the players choose to pursue out of these leads, you can use the others as secondary plot arcs, using them to give the players filler adventures between ones linked to the primary plotline (or two, if they choose to pursue two different hooks at the same time.) At each step, we repeat this process – from where they are, where are the points where the story can easily branch? The Nessian Dynamo plot splits when they discover that it burns souls, something the creators consider a benefit. Do they want to claim it for themselves, destroy it completely, or find a way to modify it to burn evil out of a soul instead? Will they let the church of Pharasma know, since they’ll have a vested interest in something that changes the fate of souls, or the church of Abadar, who will likely want to analyze how such a device impacts civilization and commerce?
Each time you split the tree, it can be worth it to go back and consider how the other hooks have evolved; the Red Mantis might get word of the Nessian Dynamo and want to capture it for their own ends in disrupting the Pact Worlds and summoning the Swarm. The cultists of Father Skinsaw in the cult of Norgorber will certainly want it to provide even more tormented sacrifices for their god. So it goes; each branch brings new options and a chance to cross the other hooks you’ve crafted back into the story.
Best of all, you, as a GM, get to have a dynamic campaign that you still don’t have to worry about prepwork all that much. Players are generally delighted to get this degree of autonomy and won’t try to break the nebulous edges of the box – and if they do, that’s a plot hook you build off of for the next session.
The Decision Tree model can be a fantastic resource; I encourage you to give it a try and see if it meshes with your GMing style. (Like all tools, it may not fit in your toolkit; there’s nothing wrong with that.)