This post is mostly about putting a lot of different examples out of how to design a storyline and manage a plot and explaining them to try and give people a chance to find what may work for them in design aspects. Or at least pick the traits of each and make their own style.
First off, the Schrodinger’s Gun idea, also mentioned as Schrodinger’s Universe in another source, is the idea that the only part of the universe the players know is constant is that they can observe. Anything outside of direct observation is in every state and no state until your players observe it and get its state. By doing this, you can have your plot in flux for key points and only focus on the parts you need to as they become relevant to the player. This is sort of like Clue, you don’t know the whole story and need to go investigating a possible theory to see if anyone will challenge it.
For example: Baldur’s Gate II has a sidequest where one of your companions returns home to find his sister has been murdered, and an investigation is still in progress. His father is convinced it was a hit from a rival and tells you to kill him in revenge. If you kill the rival, you later find out that he was innocent; if you spare him, he was guilty all along. Source: TVTropes Schrodinger’s Gun
Another example: The Blade Runner Adventure Game by Westwood had several plot points (such as whether characters were replicants or not) decided either at random in each game, or depending on the choices the player made. Source: TVTropes Schrodinger’s Gun
A strategy that can help with this is Bending Stories. To quote from the article:
The idea of Bending Stories consists in considering the story as a sort of elastic band that the player is free to stretch depending on his actions. The story retains its structure but the player can modify its length and form and thus participate in the narration. In reality the story does not change diametrically from one game to the next, all that changes is the way it is told. However, the player can see parts of scenes and obtain different information depending on the particular path he follows. Source: Postmortem: Indigo Prophecy
For example: In the Walking Dead by Telltale Games, your decisions don’t seem to influence the plot at all. Your actions change some details, but the game is quick to implement them into the planned-out story. For example: If you choose to rescue Carley, tough journalist and potential love-interest, in Episode One, she plays a minor role in Episode Two and then dies in Episode Three, trying to defend Ben from accusations of theft. If you instead choose to rescue Doug, huge nerd and all-around nice guy, he plays a minor role in Episode Two and then dies in Episode Three, trying to defend Ben. Your power over the plot seems to be really limited. Source: Clementine Will Remember All of That
Now that we’ve touched on some ideas for managing the storyline in play, we should get to focusing on the actual creation of that storyline. The first is pure randomness with random generation tables like in the ‘old days’. Using charts located in pretty much any GM guide or making your own, or even going so far as to use something like the Thrilling Tales random charts with ‘Lester Dent’s Pulp Paper Adventure Generator’ which was built from the basic idea here, you can get various ideas to start with. Roll up a few challenges, randomly design a questgiver and objective and so forth, and then tie everything together. There are a large number of examples that you can get from this but it may not always fit into the story you are trying to tell. But this is where Abductive Reasoning comes in. Abduction is a form of reasoning where you start out with the result and come up with a hypothesis of why it happened. You randomly rolled up a troll in your dungeon, now why is it there? This can sometimes give you even more interesting ties to your story.
Ties are an important thing, so why not have those connections made as part of your initial plot generation. Technoir has come up with a mechanic that I really like called Transmissions. This design allows for the game to have some interesting design you may not have initially come up with by hand. The best is to look and seeing it in motion, I think, as you will see here for an overview and here for part 1 of a 2 part detailed design of transmissions.
Always be willing to look to your players for assistance in building the world. A lot of GMs will randomly create an NPC on the fly or will just gloss over people. John Wick’s book Play Dirty gives an idea for a new way to incorporate players into the making and running of NPCs, by having them making NPCs with you as they come in and perhaps handing an NPC to them when their PC is not involved. This keeps the players still involved in a scene when their player isn’t and it also allows them to try new things from time to time. You keep the veto power, sure, but giving a player of a meek non-physical character a burly ex-soldier biker type, they get a chance to push their weight around without fear of losing their PC.
Another way to put a lot of the adventure into the hands of the PCs is to borrow Overworked PCs. This is essentially a multi-threaded plot approach, in a ‘realistic’ world.
In short, offer your players a menu of adventure hooks and let them decide as a party what to focus on next. Make them feel that there’s not enough time to do it all, then have the menu change whenever they take the time to tackle an adventure just to prove that their choices have consequences.
Granted, with the Overworked PCs, you don’t want to give them too much stuff to do. If you overload the PC with too many quests at once, you’ll find they lose interest in each quest as you can see in the second Extra Credit Video on Quest Design ( Here is the first). The 5×5 Method of quest design allows you to come up with a number of plots with threads the PCs can work on. You can do something similar with timelines, or strike out certain parts of the adventure to restrict the players flow, or have a fallback variant, such as in The Legend of Zelda: A Link to The Past, what happens if by exploring the world, you happened to show up too late to rescue Zelda at the start of the game and thus now has to find another way to deal with Agahnim and save the world of Hyrule.
Of course, all of this assumes that you are able to pull one of the dirtiest tricks ever seen by storytellers. Sealing up plot holes without indicating the act of it too much. Spoony Experiment video ‘Dungeon Mastering a Great Game‘ talks about this idea somewhat starting at about 16:45. He gives ideas on how to take the plot hole and turn it into a plot point instead. Use it to become a reason why things are strange, a bit of a reward for your players for seeing a ‘flaw’ in the design, instead of defending your choice you are stating that something did happen but it was just the players don’t have all the information. Another example, to quote TVTropes about Bob and George webcomic:
If somebody who read through Bob and George somehow managed to be oblivious to the heavy Leaning on the Fourth Wall, they might get the impression that the comic had a complex, carefully planned, intricately connected plot. However, by his own admission, Dave was just really good at making crap up on the fly, and then making up more crap to explain why the previous crap was significant. Source: TVTropes Schrodinger’s Gun