One of the things I enjoy doing as a thought experiment is to look at the Pathfinder Campaign Setting, and imagine how things would be different if one world-changing event hadn’t happened. You see this in documentaries all the time: “What if the Soviet Union won the Moon race?”; “What if Columbus didn’t come to North America?”; “What if Canada didn’t exist?”, etc. It’s a sign of how mature and developed Golarion is that one can ask these types of questions, and be able to extrapolate reasonable answers from canon.
This kind of postulate has often occurred as the major theme of an Adventure Path: “What if the Runelords return?”; “What will happen when Baba Yaga comes back to Golarion?”; “What if your favorite small-town bartender is actually royalty?” The biggest “what if?” came with the release of the Second Edition of the Pathfinder Roleplaying game: “What if the Whispering Tyrant Returns?” Essentially, a single “what if?” provides an entire campaign.
One could also go in the other direction, though, imagining what Golarion would be like if certain events had not occurred. “What if Aroden hadn’t disappeared?” (I still refuse to say “died” because that is just an assumption – come on, what’s a hundred-plus years to an immortal divine being? I’m sure I’ve taken longer than that just to answer a text, if we compare based on the proportion of our relative lifespans… but I digress.) Would Cheliax have expanded into an even-more-world-spanning empire, maintaining its colonies with Arodenite armies instead of demonic hordes? Would Andoran have risen up to fight for freedom, and would they have gained independence or been crushed as an example? Would the clerics of Aroden be the heroes or the villains? I wish I had enough time to explore all of these possibilities in print.
Other big “what if’s” can be fun: “What if the Starstone didn’t turn people into gods?” Who would be overseeing crusades, and secrets, and the carousing domain? “What if technology became more widespread?” (See my previous article on time and technological progress.)
One theme that has been explored somewhat is ““What if my campaign was set in Arcadia, or Sarusan, or some other continent that there isn’t a lot of information on?” Here, the GM has more freedom in what they develop, but they still have Golarion’s framework and lore to interface with. It’s an easy way to include your home-brewed setting in Golarion should you want to.
Not All “ifs” are equal
You don’t need to do a big “what if?” to give your campaign an interesting spin. My Kingmaker campaign was moved to Ustalav because I like hexploration and I like Ustalav, so I concocted a “what if” scenario to give Ustalav a reason to expand into the River Kingdoms. It let me tie in Razmiran, the Emerald Spire, and Numeria, plus all the spooky Ustalav stuff, and still gave me a lot of background and lore I could use without having to do an entire homebrew setting.
Or, you can go the other way, and choose a “what if” that changes everything. Right now, my favorite thought experiment is: “what if the astral plane went away?” This is a major cosmological change that sends ripples into every aspect of the game. With no access to (or through) the astral plane, there is no connection to the outer planes – and therefore divine magic doesn’t work. Neither do many forms of teleportation. The souls of the dead can’t reach the Boneyard, and are trapped on Golarion forever. (Hmm, this all sounds like something a certain tight-lipped tyrant might like to bring about…I wonder if that’s why he’s woken up?) What would Golarion look like with those changes, and would it be a fun playground to explore as a GM and as a player?
(No access to the Astral Plane is one of the driving factors behind the Aethera Campaign Setting, which is a fantastically-detail space setting developed for Pathfinder First Edition. It was created before but published after Starfinder was first announced, and so it never really got the exposure I feel it could have. Still one of my favorite projects I’ve been able to work on, and my go-to “space” setting for any swords-and-lasers games.)
Perhaps the best form of “what if” involves the players in the campaign: “”What if Quinn’s PC is royalty (or thinks they are)?” “What if Rand’s PC’s birthmark identifies them as Aroden Reborn?” “What if Shay’s PC inherits the bar when the previous bartender learns she’s royalty?” “What if”-style questions applied to the PCs’ backstories can suggest all sorts of major or minor events to add to the campaign, binding the players’ lives with world events in a very personal way.