A GM's primary role in storyline creation is to set up the plot. The plot is the base of the storyline. As a GM you must remember that you are not a storyteller. You are just a guide.
With this in mind, creating a plot is fairly simple. All you need to decide is where things will get started. Don't start by writing a novel. Don't decide what you want to happen. In the beginning your basic plot might fill 2 paragraphs if you wrote it out.
Simply decide the following:
Where will the storyline begin? What world, nation, town etc..
Who are the central NPC figures in the storyline? Who will seek out the PC's for assistance? Who will the PC's likely oppose if they decide to help?
Why is the storyline taking place? This is where your Storyline Hook comes in. When deciding why events are going down, try your best to make the events something the PC's want to be a part of.
Starting with a very basic plot has a few advantages.
#1 It takes very little prep work. Taking a week to write everything out, weigh this against that, work up tons of background info etc.. is fine and dandy, however, all of this work would probably turn out much better if it were done while the storyline is evolving rather than before it begins.
#2 Work is not wasted on portions of a storyline that players aren't interested in. A GM is a guide. It is his job to provide info about the things that player characters interact with or research. While you might have tons of info that the players will never have access too, by waiting to see where they are taking the storyline you will be more likely to also have the info they need or want.
#3 Evolution of the storyline is more natural. When GM's write up a whole bunch of info for a storyline, typically they want to share it with the players. Suddenly every bar tender is an expert in the life and history of the plots bad guy, every merchant knows the origin of the artifact that the PC's are trying to locate etc.. By keeping things basic there is less temptation to become a storyteller. You will be able to share info in pieces as the players discover it rather than finding ways to give them a novel.
#4 Keeping things basic makes things easier to change later. Inspiration strikes at the oddest times. If you write everything out, there is no doubt that you will end up writing half of it over again as you get new ideas. If you have already shared the old info with the players, you will have to find ways to give them the revised info. This isn't all that difficult, however, it will create lots of confusion in the players. Giving players faulty info should be an intentional act by the GM to throw them off track or cause controlled confusion. Info should be accurate unless there is a specific reason why false info is being given out. "I changed my mind about that" is a specific reason, it's just not a good one.
Once you have the basic plot worked out, the real work can begin. A storyline should always be a work in progress, constantly evolving based on the actions of the player characters.
You might do a little work before each quest deciding what info you will give the players. You might create various encounters specifically designed to provide info. Just make sure these encounters make sense. Everyone doesn't know everything, you should have an explaination of why certian people have access to certian info.
Always take notes when running storyline quests. Players may ask questions you hadn't anticipated. Improvise answers if nesseccary. GM's should be able to think on their feet. Keep track of what improvised info you have revealed to the players. Improvised info will build the storyline much more naturally than planned info. I realize that most people can't do everything on the fly, but you should do it as much as you can handle.
There are lots of ways to reveal info, some are more realistic than others. This section won't cover every way possible, just a few ways which GM's might find useful.
History Experts: These NPC's are very handy when info is needed. Stereo-typically they will probably be a historian, sage, or scholar. Locating an expert in a big city might not be difficult, some may even advertise their knowledge for hire services. History Experts could also be people which lived through certian events. Their role in the events will probably determine their level of expertise. i.e. A grunt soldier probably wouldn't know as much about a war as a general. A general might not know as much about a specific battle as a soldier which fought on the front lines. Make sure an experts knowledge makes sense. Keep in mind that there is only so much one can learn from books. There are also limits on how much someone can know about a subject even if they witnessed it first hand.
Captured Underlings: A very good source of info. The Underlings of the bad guy will typically spill the beans if captured alive (or rezzed), assuming they can be "persuaded" to talk. Keep one thing in mind, Underlings aren't going to know everything. They will typically only have info about projects they are directly involved in. They might not know anything about their bosses master plan, long term goals, or background. The fact that Underlings will spill the beans if captured is the exact reason why they won't know everything. Knowledge will typically be determined by rank and loyalty. A lowly soldier will know a little bit and probably talk with little prodding. A high ranking officer might know tons but prefer death over revealing anything. Also keep in mind, if the Underling thinks the PC's are going to kill him anyways he has little reason to give accurate info.
Notes: Notes are considered any written material. Notes are an excellent way to reveal info because the GM can reveal exactly what he wants to reveal. When talking to NPC's the PC's will generally ask 1001 questions (half of the time, questions which won't provide useful answers). Notes on the other hand are perfect for telling the players exactly what they should know, or at the very least prodding them toward what they need to know.
Notes on Underlings could reveal orders giving PC's an idea of what is going on or where to head. Insights into what the central villian is up to are always useful.
Diaries are a realistic way to give the PC's a glimpse inside an NPC's head. They can reveal pieces of his background, clues about his plans and goals, views on the world, his enemies etc.. There is pretty much no limit to how much info a diary or journal can reveal. Obviously, creating an entire journal would be very time consuming. If PC's find a journal just give them the 'jist' of its contents. A few key passages might be useful, but for the most part you shouldn't bother with writing it all out.
Newspapers are an often overlooked source of info. Many societies have some means to inform citizens about current events. In oppressive societies, many of these publications will be filled with bias and propoganda, however, they are still useful for telling things such as who is involved, where things are taking place, when things happened, one version of why things happened etc..
Locals: Local citizens can be useful info sources. They will generally know the basics of what is going on. Keep in mind that most locals will not be experts. They can probably point the PC's in the right direction, but that might be the limit of their knowledge. Also keep in mind that locals will almost always be biased in one way or another. Their views will be based on what they have seen, heard, or experienced. Since the do not have all the facts their info and opinions should be presented this way.
A Sub Plot is a storyline within a storyline which may or may not effect to the main plot. As stated above, a GM is a guide. Guiding the PC's down one specific path can create a good storyline, however, providing multiple paths will give the players more influence over events. More influence almost always equals more activity which translates to more enjoyment.
Sub Plots are the difference between an interesting storyline and a storyline shaped by the actions of the PC's. PC's should effect the storyline in many many ways other than just roaming around finding out info and killing stuff. Their actions should create paths all over the place which will lead to future adventures and probably add depth to the main storyline.
Info Research: Searching for info can create lots of sub plots. PC's might have to travel all over the place before finding what they need to know. Each journey will produce new dangers, experiences, and possibly even more subplots.
Note: If PC's simply march toward their objective gathering info as they go, your producing fewer chances for sub plots. Make the PC's step off the main path to find things out.
Gathering Allies: Searching for allies can create all sorts of subplots. Finding allies is a sub plot but perhaps allies won't help the PC's unless the PC's help them first? This could create a side adventure. Should the PC's take the time to gain the ally or proceed forward on thier own?
Unrelated Enemies: PC's have a knack for insulting, or killing things. If the PC's kill an orc scouting party as they move toward their main storyline goal, the orc tribe is probably gonna be ticked off. Maybe the orcs might hunt them down?
What if a valuable item disappears from a town that the PC's just passed through? Maybe the townsfolk will remember the strangers and John Law will try to track them down for questioning? What if the PC's kill John Law?
I guess you get the idea. For ever PC action, there is a reaction from the universe. Showing as many of the reactions (good and ill) as possible will create an awsome storyline.
Your basic plot will provide a goal for the PC's to work towards. Subplots give players descisions and choices. This is your job as a GM. Give the players and PC's as many choices as possible.
�2001 Joe Pom