A July 2022 renovation of the tag and others has changed the context of this question. It is now obsolete. Please see the following question and the link under "Conclusion." If we can't burn the "reality check" tag, can we rename it?

A comment to Reasoning about the thermal conductivity of a rigid body states,

I’m voting to close this question because it has "science-based" as a tag, but puts in conditions that explicitly deny known science, specifically, that contradict relativity.

This site regularly assumes that questions must conform to real-life, and so I feel it's important to clarify the tag summary and the tag wiki. The summary reads:

For questions that require answers based on hard science, not magic or pseudo-science, but do not require scientific citations.

Which suggests that the first linked question should be closed for failing to meet the expectations of the tag. However, the wiki includes...

Questions with this tag should be answered, as far as possible, based on known scientific facts or reasonable extrapolations from those, but answers are not required to provide scientific citations. ... Most answers on Worldbuilding are expected to be based on logic and, to some degree, science by default, so even questions without this tag may receive scientific answers. However, the use of this tag indicates that the asker wants specifically science based answers....

Which is a lot less demanding than the summary suggests. My question is based on the following investigation, "Does it make sense that we should or should not use the tag when asking for a real-life science-based answer to a question that has worldbuilding rules that diverge from known science?"

My opinion: It is my opinion that tags scope the answer, not the question. This, despite the fact that most wikis (including that for ) talk about their attachment to the question. If I'm right in this opinion, then a casual effort to begin cleaning up wikis so they reflect this would be appreciated. If my opinion is in error, then we have a problem, because there isn't a convenient tag that expresses the idea, "given the rules of my world, does this circumstance reflect (or could it reflect) real-world science?" In a sense, the OP might have needed to choose rather than , but that, too, would not have reflected exactly what they were looking for.

Question: Should the tag summary and wiki be updated to reflect the OP's desire that answers should, as far as possible, reflect real-life science rather than demanding that the answers reflect only real-life science? Said another way, should the wiki be modified to reflect the summary, or should the summary be modified to reflect the wiki?

1. Please note that the first linked question is on the verge of closure due to this very issue.

2. In a sense, I'm asking where the line between "science" and "pseudo-science" is drawn. All world rules that vary from what we "know to be true" in real life could be said to reflect "pseudo-science." However, that's kinda the point of this site... to help people develop an alternative-science (aka "pseudo-science") that can be consistently used to develop stories. It's a tough row to hoe if we start punishing people for trying to create a world rule that both meets their needs and can be expressed in the context of real-life or varies as little as possible from real-life.

  • $\begingroup$ I hope I understood everything right! If it seems like I went off base let me know! $\endgroup$
    – elemtilas
    Commented Jul 17, 2021 at 19:48
  • $\begingroup$ A July 2022 renovation of the reality-check tag and others has changed the context of this question. It is now obsolete. Please see the following question and the link under "Conclusion." worldbuilding.meta.stackexchange.com/q/9790/40609 $\endgroup$
    – JBH
    Commented Jul 17, 2022 at 23:34

3 Answers 3


If we define "science based" as adhering to "all world rules adhere to real-life science" then we're basically creating a (near vs actual) synonym for the Hard Science tag. The only distinction would become one of need for equations and papers while the other wouldn't. It would be Science Lite.

Because Worldbuilding deals so frequently with the irrealis --- dragons and winged people being commonplace hereabouts --- and many of these questions are indeed tagged as Science Based (this dragon query, e.g.), I'd argue that respondents to such a science based answer ought to approach the question more liberally.

For example, a respondent should "build upon" science --- use one's knowledge of biology, anatomy, physics and so forth --- even to the point of creating a new science, in order to give the best answer. We should not be limiting ourselves to real world science --- that's what Hard Science is for.

The Hard Science answer is "no, and here are the relevant physics equation and papers describing why dragons can't be". The Science Based answer is going to have to work with the math, but ought not be limited to it. The science and the resulting answer don't have to be realistic.

While it's true that many questions here demand a real life scenario, many others do not. Science, in the realms of fantasy and even sci-fi, does not need to be limited to what we know of science in the real world. While questions of these kinds ought to be treated seriously in their scientific principles, there's no reason to stop there. This is also a highly creative forum, and good answers ought to call upon creativity as much as or more than mere number crunching.

As for your subquestion: pseudoscience is just science that works in some other universe. There is absolutely no reason why it can not be called upon, in a serious and sober fashion, to be put to the service of a fictional world in the same way ordinary science ought to be.

Take-away: we as respondents need to apply creativity as much as scientific sobriety when approaching queries that don't fit the 100% real world model.

I'd vote no for this one, because science must feed art, rather than dominate art.

  • 1
    $\begingroup$ As usual, we're on the same wavelength. I feel that science-based has, indeed, become a practical synonym for hard-science in that the answer must reflect real life. Evidence of this is the number of questions asking whether or not some fantastic creature "can evolve" or "can exist" and the science-based tag is supposed to indicate some magical effort to conjure the creature in the real world. It's almost as if the Anatomically Correct Series has stopped being a means of rationalizing fiction and has, instead, justified the idea that all fiction should reflect fact. $\endgroup$
    – JBH
    Commented Jul 18, 2021 at 3:12
  • 1
    $\begingroup$ I'd be delighted if the science-based summary and wiki reflected what you explained: that science should be used where possible, but the answer is not bound by science. In other words, "You know, the way an Eagle's wing is built is a good start for rationalizing your dragon... it just needs a few tweaks like these..." is the kind of answer science-based should produce. $\endgroup$
    – JBH
    Commented Jul 18, 2021 at 3:14

You are welcome to append or disagree but my interpretation of the three tags is that although there is overlap, we can in fact draw logical and rational lines between the categories based upon the question, not the answer. Here is how I see the three sorting boxes drawn out:

Hard science

The question asks for an expert opinion on the effects known scientific truths would have on the world-building problem. e.g., Given 2 million years, could komodo dragons evolve feathers and wings? An expert response would stay within the bounds of known evolutionary science.


The question asks for an expert opinion on the effects known scientific truths would have on the world-building problem, given the exceptions noted in the problem. e.g., Given the random evolution of an “X-factor” gene that gives reptiles telekinetic abilities, could a komodo dragon effectively fly? (the problem states some costs and limitations of their scientific exception - telekinesis) An expert response would stay within the bounds of know science, and incorporate the stated exceptions. And let’s be honest, no worthwhile science fiction can stay perfectly within hard science bounds. So this tag is almost a default.

Reality check

This question is a go/no-go question that allows the problem to define exceptions to hard science, such as telekinesis, and whatever is not stated as an exception is implied to be constrained by hard scientific truths. e.g., A space-time distortion caused huge tectonic disruptions on earth and altered physics to make komodo dragons telekinetic. Now after millions of years living on sheer cliff faces, they terrorize the skies like wingless Chinese dragons. Is this realistic?

To me it is worth keeping the go/no-go test separate from the science-based questions simply because it contributes to concise questions. Wording a science-based problem in a way that expects a go/no-go is tricky.

As to a line between science and pseudo-science, I don’t think that is this question. That line is simply drawn by the scientific method. Pseudo-science doesn’t adhere to it, science does. Of course as new evidence always arises, things can cross over this line in time, in both directions.


Just follow the language

The tag called for "plausible answers based on real world science". So long as that's how people expect answers to be given, it should be fine.

If you ask "how does my magic wand work?" and the responders say "magic! it can do anything", well, that's not based on science. If they say "how can you ask how a magic wand works when it's magic?" that's not based on science either. They need to either fire up the miniature particle accelerator or the acoustic holography projector, or something sciencey, or shaddup already.

Similarly if you're going to ask how much wood a woodchuck would chuck ... then insist it can't chuck wood, that's not going to work. You're either willing to watch your buddy get exercised on a super-sized hamster wheel rigged by clockwork to a mini trebuchet, or give it up already.

Where it gets sticky is if someone says "I have this magic system and how does it work with science", and doesn't give enough details about how to write an answer based on science. If you can turn somebody into a toad by magic, great, but "how does the science work?" ought to give some detail so you know if you're explaining where the extra mass goes (hot dark matter) or whether the toad is ultra dense (concealed condensed matter robotic skeleton) or ... well, let's say there are options. I'm not saying you have to close questions, but we should expect that if people want a science based answer they can give us an idea of what general sort of science based answer they want, or else brace themselves for a hailstorm of random frogs splitting off from alternate dimensions.

  • $\begingroup$ The language in what, Mike? This entire thread was made moot by the recent changes to the science-based, hard-science, science-fiction, reality-check, and internal-consistency tags. Why are you answering a now irrelevant question? $\endgroup$
    – JBH
    Commented Jul 17, 2022 at 21:48
  • 1
    $\begingroup$ I saw this at the top of the list. I can't say I was watching for policy changes. Are threads closed or otherwise marked on Meta if they aren't taking answers? I should note though that I was speaking in favor of the text that currently appears when "science-based" in a rectangle is clicked. $\endgroup$ Commented Jul 17, 2022 at 23:13
  • $\begingroup$ This one is marked. The very first line of the post. $\endgroup$
    – JBH
    Commented Jul 17, 2022 at 23:15
  • $\begingroup$ Sorry, but when I look at it, even now, that seems to be suggesting the new text had these problems which needed to be considered. I suppose if I'd looked at the posting date and the date mentioned in the first sentence I could have logicked it out, but ... not the clearest way to close a thread. $\endgroup$ Commented Jul 17, 2022 at 23:19
  • $\begingroup$ Fair enough. I can make it more clear and propagate it to the many now obsolete questions. $\endgroup$
    – JBH
    Commented Jul 17, 2022 at 23:28
  • $\begingroup$ That's better. I wonder if Meta should have an "obsolete" tag. $\endgroup$ Commented Jul 18, 2022 at 21:51
  • $\begingroup$ I'd love one! Especially if it could be the red only-moderators-can-use-it variety. But it's likely a low priority. $\endgroup$
    – JBH
    Commented Jul 18, 2022 at 22:07

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