BLT Worldbuilding
The title for this essay is a nod to a Reddit post I saw recently, titled "How early in human history could we have made BLT sandwiches?". The top response included this quote:
With extensive trade networks and limitless wealth and effort, it might theoretically be possible for the right pre-Columbian inhabitant of the Americas to take two pieces of corn flatbread, smoke and/or cure some peccary belly, slice it thin, fry it up, pair it with tomato and wild lettuce, while also independently pioneering the famously finicky process of furiously beating oil and egg to a smooth emulsion... but the degree of culinary knowledge and access to ingredients is well past plausibility, and it STILL wouldn't really taste or crunch like a BLT.
This post is a good exercise in appreciating where food comes from and the history and cultural interchange that goes into inventing something as seemingly simple as the BLT, but what really got my gears turning was the idea of this "pre-Columbian BLT," that you could have something kind of like a BLT without wheat, pigs, or common Eurasian lettuce. Which, in turn, made me reflect on how we as worldbuilders decide what to include and exclude from our speculative worlds, and whether we might be missing out on interesting ways to build out those fantastical settings.
Flora, Fauna, and Food
Food is one of the easiest ways to see how decisions about flora and fauna impact the set dressing of a speculative world, even when a creator might not realize they've made a decision at all. Most generic fantasy settings are pastiches of Medieval Western Europe before the Columbian Exchange, which means before "New World" foods like tomatoes, potatoes, avocadoes, corn, chili peppers, or chocolate made it back to the "Old World." Some GMs (and other kinds of fantasy worldbuilders) may include these foods in their fantasy settings without realizing that this is, technically, anachronistic. They would be in good company: Middle Earth has potatoes, and Westeros has corn and chilies, despite both worlds being serious Medieval Europe pastiches.
Some worldbuilders, aware of these crops' histories, may deliberately exclude these kinds of foods from their constructed settings, in the interest of "historical accuracy" or "immersion." Others may justify it by including a Fantasy Americas in their constructed world.
What I'm proposing, inspired by the BLT discussion, is to go beyond medieval pastiche, or attempting to replicate a stereotypical version of historical periods of places in the real-world (especially Medieval Europe). What would a meal look like for your PCs in a culture without wheat, or most farm animals? The Americas, pre-Columbus, are a proof of concept, but not the end of the road: you can set your game in a continent with its own mixture of Old World, New World, and completely invented flora and fauna.
Deliberate Anachronisms
I think the matter of food and where it comes from in fantasy settings hints at a deeper issue with what we include and exclude in speculative worlds, and how much more visible the inclusions are than the exclusions. The Forgotten Realms, Golarion, Tamriel, et al. are all worlds which can be summarized as "Medieval Europe with dragons" or wizards or zombies etc. etc. But there are a lot of aspects of the Medieval world which are left out: firearms predate plate armor, but you are far more likely to find plate armor in a fantasy game than guns, even gunpowder. This is probably an example of the "Tiffany Problem": people simply lump guns into a more recent historical epoch, and consider it anachronistic when they show up in Medieval-inspired settings. The solution to this problem is to reject outright the idea that one has to simulate the Medieval world. Your constructed setting is made-up, after all, and has no obligation to historical simulation the moment a wizard or dragon shows up.
So take ownership of your anachronisms, and include or exclude things in service to your storytelling and the richness of your setting, rather than because of convention or to appeal to the historical preconceptions of your imagined audience. If you want to exclude firearms from your campaign world, exclude them. And think about what else you might exclude: what about the wheel, ironworking, or writing? Historically, the Incan Empire was able to prosper without any of these things. Just imagine what you can do when un-limited by history.