So your gamemaster (GM) has sent you and your party back in time (or to a low-technology parallel dimension) in your roleplaying game (RPG); and, for one reason or another, it’s become pretty clear that you’re going to be able to mess with the ‘true’ timeline however you like.  Your party has probably already decided to ‘invent’ gunpowder, distilling, and antiseptics, mostly because everybody usually does in these circumstances and a player can reasonably claim that his player-character (PC) might have that information carried around in his head, thanks to him having the relevant skill.  Which is perfectly fine, but what disruptive technologies can the rest of the party produce?

Well, let’s take a look.  Note that this list is hardly exhaustive, and probably cannot be exhaustive. Innovation happens in every field of human knowledge. What these are are mostly innovations that don’t require much in the way of specialized equipment; merely having the required skill should be sufficient. Also note that the assumption in this case is for the standard late Medieval European period, partially because many fantasy worlds in literature are associated to that technological setting anyway.

More examples on the next page.

One last point: there’s a passage in Eric Flint’s 1632 alternate history series where he noted that time travelers can have a major advantage. Which is to say, they know what techniques or methodologies work.  And they’re going to be visibly confident that those methodologies work, too.  This instinctive confidence can be a real help for players who are trying to convince their GM to let the party get away with an innovation that’s particularly envelope-pushing…