“Hard science fiction” are stories that are told from within the perspective of scientific possibility.  In other words, anything that happens is to some degree plausible, scientifically, based on what we know — and, critically, do not know about the nature of our universe.

However, when we get very far out from the present day, this falls apart almost immediately.  Partly because of things like the fact that we haven’t yet met any aliens, or experienced certain common elements that can be written about.  But also because physics is so dang complicated!  There’s a lot that is known in cosmology, but as a non-scientist it’s hard to keep track of what is the consensus, what is a realistic theory, and what is just an interesting idea.

Turns out that ideas like String Theory, which have been captivating the popular imagination (including my own) for decades, are completely junk and have always been so.  It also turns out that dark matter isn’t some theory to explain math that didn’t quite work yet, but instead is just a bunch of literal observations that are all consistent with one another.  Dark energy has no relation, it’s just “missing energy” that is confusingly named, and perhaps the leading theory is that such energy is in transit through space?  It’s really hard to be sure on that.

It is incredibly hard to keep up with all of this, and the understanding of those of us who have written in this universe has always been non-professional in general.  None of us are physicists.  So with that in mind, the details of this universe are going to and have diverged from what known-reality is over time.  The general stance here is that it’s better to keep this fictional universe consistent with itself, while reconciling with improved understandings of science as possible, but to stick with faulty understandings where it would require a giant retcon.

I’m a fan of both Star Trek and Star Wars, but essentially you can tell that a large number of writers working in both franchises kind of go “well, I want something to happen a certain way, so insert some technobabble here.”  And often the technobabble doesn’t make a lot of sense.

So let’s talk about plausibility in the Arcen series:

• The protagonist of both The Last Federation and Starward Rogue is a Hydral, a large sentient creature that has multiple heads that look dragon-ish and which do in fact grow back after being chopped off.  Unlike the fantasy beast, more heads don’t grow back; it’s purely regenerative.  Probably the thing that pushes the limits the most is that a head is able to survive without a body, but placed into a mech suit that has a radio link to the rest of the Hydral.  This is kind of me pulling a Star Trek, and that’s the way it goes, I suppose.
• The Last Federation also depicts a single solar system with nine habitable planets (although gas giants being habitable is a complex topic), and each planet has an individual sentient race on it.  This is unlikely in the extreme, and the lore calls this out and notes that there’s no way that solar system could have evolved that way naturally.  This is something that needed to be the way it is for gameplay reasons, but it also raises questions of potential intelligent design in that specific solar system (kind of like the Obin in the Old Man’s War series).
• We don’t really represent time in any meaningful way in the AI War games, and energy transfer is kind of the same thing.  In other words, events happen in a matter of minutes rather than over months, flight times are massively reduced, and you don’t have to worry about how energy is distributed through the wormhole network.  Once you build a new reactor, you just have energy everywhere.  Uh… yeah, that’s definitely not hard sci fi.  The way that wormholes work also has a pretty loose relation to reality, but it makes for useful storytelling and is similar to many other stories with similar types of FTL.

When players ask me how energy or something like that works, I do exactly what the Star Trek writers do, and I start pulling stuff out of my rear end based on what I know about current science and theoretical science.  But most importantly, I also note that certain things make for good game mechanics, and so the entirety of those games are basically an abstraction of reality.

I used to consider the Arcenverse  to be hard sci fi, because at least it’s trying to be consistent.  But I think maybe a better term would be “Internally Consistent Sci Fi,” overall.   Most of the time there’s some attempt to also root the science of these games in reality, but sometimes that goes out the window on purpose, and other times I simply have a large misunderstanding of what the current state of physics and cosmology actually suggests is real. 

The ships have reactors that burn dark matter, but there’s no consensus yet among physicists on what dark matter is — they know it exists, and certain things about it, but a lot of the rest is theoretical.  The Arcenverse posits a very fanciful and unusual version of what it might be, because it makes for interesting storytelling.

Conceptually, no ships are breaking the speed of light, and lightspeed limitations are partly related to lore about the AI and how it’s able to be surprised.  The aliens are truly alien, and tend to not be humanoid in the slightest, but there’s nothing we know about that suggests a sentience could not arise in such a way.

The Arcenverse is meant to be internally consistent if nothing else.  The term tachyon has been assigned a meaning, and it has only that one meaning rather than being used for many different convenient plot devices.  The alien races, their motivations, and what happens with them all follow my own understanding of what we could actually run into out there.  The Arcenverse subscribes in general to the Dark Forest theory of why we don’t see more alien races than we do, and that helps me get away with a lot.

When it comes to questions of “how something works,” I specifically will avoid giving a definitive answer for as long as possible, so that I have more options for story possibilities in the future.  If I prematurely answer those questions in a canonical way, then the possibilities for the future are diminished.  I want lots of flexibility in the future, so I only answer what I need to for each story.  Unlike Star Trek, I work really hard to not say that transporters work one way, and then later undo that (not that the Arcenverse has transporters).  That’s a luxury I have since I get to steward this narrative universe by myself, and don’t have to worry about dozens or hundreds of writers I’ll never meet not understanding my prior intentions.

At any rate, when it comes down to it, I place gameplay first, and then make sure that it makes sense in the scientific context of the Arcenverse.  And I’m really good at coming up with bs scientific explanations, on the spot if needed, for pretty much anything.  To me, the key is not taking the bs too seriously, but at the same time respecting it and not just saying anything goes.