I base Prep on player obligations and current situation/previous session.

I have an overarching ideas of places the story might be going, but they often change or evolve based on character actions, narratively dice and random ideas.

The most usefull thing I do is roughly knowing the location the characters are in and having a list of random npc names and aereas or Cantinas or docking bays or what would be likely in that place. Those liste are Great helping tools for improvisasjon, either for me or to ask my players to elaborate on.

A random encounters that would come up or two os also nice to have

I write down the obligation of each character and try to think how it might apply in the up comming situation and where the last session ended. I often write short intro scenes for each obligation or Connecting obligation and if there is no obligation. The scene either starts off right after the last session ended or I fast forward a few hours or days in time depending on thescene, story and how the obligation affects it in the given situation.

Sometimes the scene is or involves a combat encounter, chase or other skill-based encounter.

Sometimes I take players into the kitchen and tell them npc secrets or things that will created drama between the characters. Maybe an objective from their obligation npc or another employing npc.

One time I took them into the kitchen and gave them each a que, if another player said a specific word or Something, that would give them a strain, I think it was after they failed a fear check. Then if they strained out, they came with me to role on a table to see what happened to them, like they could only talk in questions or could only use two specific sentences to communication. That was fun. They were in a dark, force infused swamp jungle that made them mad that time.. Good times.

It kind of depends on how much time I have...usually, I write out an outline of where I want the story to go. I'm currently using OneNote, which is my online note system of choice. This at least helps get my thoughts in place, and also helps me solidify the description of the areas the players investigate in my mind. I think description is one of my weak points, so I want to be sure to get that down. I'm sure enough about my improv abilities that if needs be I can run just based on a quick outline.

More often, though, I'm more on my game, which means I have more time. I put up the NPC wounds, strain and soak on a spreadsheet that I can consult, and then roll up Initiative for each combatant NPC. I also make sure that the Obligation that I rolled comes into play somehow, and I also have a secondary and tertiary Obligation rolled just in case one or two players make a no-show. I also try to make sure the adventure has a moment where all of my players can shine. I also usually try to have a map or two ready for the players. These can either be a pre-made map or one I put together. I make sure there are tokens to represent the bad guys,

If I'm really, really on my game, I'll be thinking about how the players can throw the adventure off-track, and try to have some contingency plans in place for when they do. What happens if they don't try to steal that Imperial ship and instead decide to hold the director of the spaceport hostage until they get a ship? Stuff like that. I try to let them have free will, but provide a very good reason for them going in the direction that I want.

For me I don't necessarily try to tell "My Story" when I GM but to just put the PCs in a living and breathing universe and see how they fare.

This involves tracking multiple factions and their major characters, and their motivations and agendas between sessions, completely independent from the PCs.

Like the Fleet of a Grand Moff, a Rebel Commander and his platoon, a Black Sun Vigo and his operations.

What are their goals, their strenghts and weaknesses, what resources do they have, their actions and reactions and wether they succeed in those or not.

Stuff like that.

For the PCs, I evaluate if their actions had any significant impact on any given faction and what the consequences of that might be.

Obviously you can't go completely without plot, so I try to have multiple red strings laid out, that the PCs can choose to follow or not..

I also preprep some contracts for when the PCs are just in the mood for a good old fashioned bounty, wich for me are easy to facilitate, since the parties most prolific character is a Assassin Bounty Hunter.

What really helps to move a session along, is to just have modular characters, events, and encounters at the ready to throw at them.

Additionally I think about the planets and locations that the players are most likely to head to next and inform myself thoroughly about them.

What kind of species can you find there, does the empire have an influence here and if yes to what degree, local culture and potential local conflict.

All of that seems like a lot, and while I try not to overprep, it is very useful to have a kind of catalog that you can just throw things from at your party.

I spend probably 3 to 4 hours prep hour of play. Our sessions run 4 hours so it's quite a bit of work. The overwhelming majority is background. I have a plot line in mind but allow a lot of wiggle room so I have to prepare lots of alternatives. Locations, npcs, subplots etc. I keep a file on every world with info generated, they fill up fast.

Players are on Cona right now and about to tangle with Imperials. Good chance they will have to run. I've got a half dozen fleshed out locations waiting for them to choose from. (ie. Mining instalation, arcona nest, orbital catapult station, hydrofarm, etc)

In my experience you can't prep enough.

For me, I try to focus on the motivations of the known NPCs, and what all might be going on in the background regardless of whatever the PCs might or might not be doing.

I also read up on the planets that they’re going to be on, and the specific locations on those planets where I expect them to be. This might be from the Star Wars Atlas, or Wookieepedia, or whatever.

I run through various scenarios in my head regarding how certain encounters might go.

But I actively try not to get locked into anything with regards to any of the above, because everything will change once the PCs get involved.

This preparation might be just reading the book for a few minutes just before the game, or it might involve a lot more research and gathering of materials in the week leading up to the game.

It all depends on how things work out that week.

I prep extensively for sessions. I write adventures from scratch, mostly set on planets that I've created myself. I never run completely open sandbox games, but write adventures with a beginning, a middle and an end. They frequently offer branching options and the opportunity to do various tasks in any order (with situations changing based on what the PCs do first and last) but there's always a structure to it. I populate the adventures with a variety of NPCs and frequently have various groups and factions operating at cross-purposes to each other, to the point where my players tend to comment on it if there's only one clear opposing group or faction.

Mostly my campaigns are set in relatively limited areas of space, such as one particular sector (with the occasional excursion to other locales) that I make up from scratch. I write sections describing each individual planet, draw a sector map with hyperspace routes and travel times so my players can make informed decisions on where to go and how long they need to get there. I tend to populate these sectors with multiple groups, like the Rebellion, the Empire, crime syndicates, mercenary groups, pirate bands, corporations, guilds and anything else I can think of, and them I make sure that any large-scale decisions my players make have permanent and noticeable impacts on the setting they're in.

It's a lot of work, but I wouldn't want it any other way.

My sessions run about 8-10 hours long each, and we game about every other weekend. I use the Obsidian Portal to keep a lot of my stuff on it. I also use OggDudes CharGen, so that really helps creating NPCs!!!

I would have to say I don't spend to much time on each session. Maybe a few hours. I have the over all plot line. They are part of the mob on Nar Shaddaa, and work for a minor Hutt Crime boss, who is trying to move in the world. They also own a bar.

We started out using Obligation, but it has kind of fell away.

I usually just come up with an adventure outline. A basic gist of what I want the guys (well, we do have one girl too!) to do. So a basic plot hook. And maybe then a specific encounter. The rest is pretty much made up on the fly. I have a couple of decades of experience as a Star Wars Game Master, so this really helps out. I found that that usually go off the rails anyway. So why have rails? Like this past adventure, I wanted a player to go recruit some thugs that had tried to mug him before. That was one of my big plans!!! That was it. It turned into a fun RP encounter with him and the Hutt Crime Boss, then him and the thugs and the Holo-Pool table joint. He is pretty much a bruiser with three ranks of Fearsome and a mafia Made Man!!! So when he walked in, he really walked in!! LOL. This is the kind of guy that commands respect, and if not he will bash your bloody skull in with his club! Then go take his mother some flowers at her nursing home.

I had some other ideas and things ready for the day, but for that encounter, I didn't have anything ready other than the idea that he was to go recruit the thugs that tried to mug him before, and he gave them all a good thrashing! Now they work him! No stats, no names, I did have some species, from the last encounter. But no real work into, and it was a blast!

I really let the players help tell the story. I'm not adverse to have the players show up and go, ok guys, so what are you doing today? That only works with the right group though!! I have had it work in the past, and it was really fun!

I was hoping to do some more work in laying out the city they are in, and even making a map of it, and lot more details. I was hoping this campaign could be running for a awhile, but things may be looking like we may only have a few more sessions left, so I'm not too sure yet how much more work I'm going to put into the background of the campaign, and will just probably work on the finishing up the storyline. They did discover that their Hutt's medical droid has been slowly poising him his whole life, and it has his cousin, a upper Crime Boss who gave him the medical droid when he was younger to "save his save from a rare disease". Gotta' love those Hutt's!!!! LOL.

I start from obligations (or rather an expanded form of obligation that I call side stories) try to work at least 2-3 of them in, come up with an outline which I'll post in the game masters section of these forums with a request for ideas from my fellow GMs for example this https://community.fantasyflightgames.com/topic/206132-please-help-me-brainstorm-for-my-next-session-mid-to-late-april-2016/ thread. I'll send emails to my players to get their feedback on my ideas for plot points related to their side-stories (the story is about the PCs, and I want to make sure that THEIR story goes in a direction that they are ok with, it doesn't mean that they know all the details of their side stories in advance and I don't tell them the plot points of other PCs side stories in advance except when they interact with theirs, so there are still plenty of plot related surprises at the table)

then with plot outlines in hand I start on encounter design. This includes

• looking at the talents my PCs have so that I can give them opportunities to use those talents (opportunities that aren't an "I win" button for the encounter) especially the flashy talents
• I may make some nemesis NPCs,
• I look for maps (e.g. Maps of Mastery or stuff that I got from the WotC miniatures game fan "holocron" site before it got taken down) appropriate to the encounters, I may end up printing maps or terrain cards at Office Maps, generally I try to have maps for 3 to 4 encounters per session (sessions last 3-4 hours)
• then I start looking at my roughly 500 WotC star wars miniatures, these might inspire rival or nemesis NPCs
• choosing music for the encounter

encounter design feeds back into plot development. I often make partial scripts... and have a one paragraph cool speech ready for NPCs or to suggest for PCs if they can't think of something cool in the moment for example this exchange between a falleen gunslinger NPC, PC (Thad Bane) and Cad Bane (PC's uncle)

Kynxa:

As for Thad Bane, I just want you dead. You don’t deserve your reputation as a badass quick draw gunslinger; it just got handed to you on a silver platter because you’re Cad Bane’s nephew. Well it’s time I got famous, and unlike you I’m going to earn my reputation by burning you at high noon and then also outdrawing your uncle when he comes to avenge your death. I’m fast enough to do it. Of course, if you’re scared you can go peacefully but to be honest either way you’re going to get fitted for a pine box. If I were you, I’d choose to go out in a blaze of glory, after all there’s a slim chance that you could outdraw me and save your friends. So you’ve got to ask yourself one question: “Do I feel lucky?” Well, do ya, punk?

Quickdraw showdown between Thad and Kynxa (cue the good the bad and the ugly theme music) Kynxa will probably outdraw Thad and hit him but not put him down, then Thad’ll shoot her and drop her… says something cool like

Thad:

There’s something I learned when my father died drawing down on my uncle, shooting first is good but shooting last is better. When you’ve only got time for one shot, you need to make it count. As a gunslinger, fast isn’t useful unless you’re also deadly accurate.

Kynxa yells “shoot them, shoot them all now” and out of nowhere blaster bolts strike and kill 3 corporate muscle who were reaching for their weapons.

Combat may or may or not ensue, if so, some corporate muscle accidentally shoots a teenage girl in the chest, then someone shoots or slices the muscle, whose bleeding out. Both are dying but neither are dead yet, the girls needs a heart to survive, will M4-RK and ST-3V3 transplant the heart of the muscle into the dying girl to save her life?

After the combat (while the medical emergency is being dealt with) Cad Bane talks to Thad over a comlink, tells them that:

Cad Bane:

Thad, Czerka was really just interested in Tal, and the rest of this is for show. Oh there was a potential mining contract and ore sales on the table, but that wasn’t what motivated Czerka to send serious muscle all the way out here on such short notice. Just thought that you should know. I’m proud of how you handled yourself today Thad, I’m not always going to be around to protect you. I was this time because I heard about the live bounty contract that Czerka put out Tal. I figured it’d be Kynxa who took it. There are very few hunters out there who have both the talent to be a serious threat to you and are foolish enough to go after my nephew. Oh and Kynxa, you WEREN’T fast enough to outdraw me. (Head shot kills Kynxa.) Sorry about the mess Thad, but I had to reinforce the message that death is the price of shooting or otherwise trying to kill my blood.

BTW the encounter played out exactly according to the script and the player of Thad Bane loved the suggested text I had for him, and after he read it, the other players were like "ooooh dissss" and "burn" note that having PCs diss NPCs is cool, having NPCs diss PCs is not cool... except to have an NPC issue a challenge to a PC's reputation, and setting up the scenario where the PC is likely to come out on top after the NPC "draws blood" without taking them down (for example by giving the PC a lower damage weapon) so the PC has the opportunity to "spit some blood" and comeback with an "Is that all you've got" statement before they pummels the NPC. The point is when you have a NPC insult a PC the scenario should be set up to builds up your PC, help them feel like a Big **** Hero, rather than tear them down.

Note if you have a "script"/plan for an encounter, the script should generally be to give the players what they want. One of my Players loves to be the person with all the answers, he's playing a human female scoundrel fixer master of intrigue and the one who often gives the other PCs their mission, So he has access to more information than the other players (I feed him a bunch of details through email before the session), for I'll tell him in advance what NPCs seem trustworthy and others "well there's something off about him, you feel he's untrustworthy even more so than usual for a bothan spynet agent, but you can't put your finger on why," so he'll know who he should plan extra precautions to deal with. His character is the one with the contacts who can get them the plans for the facility they need to break into, that sort of thing. In the second session, I scripted that character taking mad crazy precautions that the other PCs found out later paid off big time. Another player said that they love playing with him because he's awesome and steals the show (in a good way) when he's there (the player lives in a different city in New Mexico so can't make every session).

so the point is scripting is less offensive when it's collaborative with your players, when you're intentionally writing the script to give the players what they want for their characters, that doesn't mean they always win, often several narrow losses or stalemates followed by an eventually narrow victory against the same opponent is a lot more satisfying than crushing the opponent the first time they encounter them.

Oh yeah, having frenemy nemesis NPCs is great, someone who they may compete with sometimes and other times collaborate with.

then there is good prep, for example star wars ice cubes ("look it's captain solo and he's still frozen in carbonite") for your drinks, and you have to vary the menu.

So that's what goes into preparing for a session for me.