In a sci-fi book that I am still to write, can I use the word 'illusion' to denote extreme cases of mind trickery where such an 'illusion' can alter things and space around, example: people are able to travel faster, fight of monsters, feel pain from pricking etc.? What's the work around if it's not possible? I don't want to use magic.

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    $\begingroup$ You can use whatever words you want for anything you want in your story. As is, I don't think this qualifies as a complete question. $\endgroup$
    – Nepene Nep
    Commented Jun 9, 2023 at 9:03
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    $\begingroup$ It's currently half off-topic, half need more details. Understand that you're mostly free to use whichever word you want in weirder worlds. A great example of free word usage lies in the old, very old woodruff and the Schnibble point&click game. To be more on-topic and have more details, you'd need to think more with your culture, its origins, and its relationship with said "illusion", so we can make some kind of etymological work instead of a writer's choice ^^. $\endgroup$ Commented Jun 9, 2023 at 9:27
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    $\begingroup$ The point of an illusion is that it is not real. If the alteration of the duration of travel is not real, then it may be and should be called an illusion; but if it is real, calling it an illusion would make the story very hard to understand. Not impossible, and definitely allowed; but you may want to put yourself in the shoes of the potential readers, and ask yourself whether they will find the story sufficiently rewarding to compensate putting up with calling chairs roofs. VTC as absolutely not about worldbuilding, but rather about poetry. $\endgroup$
    – AlexP
    Commented Jun 9, 2023 at 10:47
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    $\begingroup$ As other comments mention, you can make up your world's lingo as you need to. More details may help us understand your usage better and make better recommendations. If this is mainly a word choice question, you may also want to check the English Usage SE. $\endgroup$
    – Atog
    Commented Jun 9, 2023 at 16:31
  • $\begingroup$ If a state of mental trickery allows people to change reality, then it's psionics, basically magic achieved through mental manipulation of the world. There is no middle ground. $\endgroup$ Commented Jun 20, 2023 at 20:19

2 Answers 2


Wikipedia defines illusion as

  • distortion of one's human perception of reality
  • a misrepresentation of a true sensation
  • they are generally shared by most people

When you talk about altering things or space, you are changing the physical perception of the concerned things or space. After the change everyone would observe the induced change but this does not always mean it is the new reality. Reality is still illusionary. Every velocity in the universe is relative and is reality only in one frame of reference. For some other frame, it is not even an illusion (a perceived reality) but something pointless. Even the absolute speed of light is absolute only because of the different perceptions of time in different frames. And all this is not even mind trickery but actual physical phenomena.

Therefore it is safe to say that whatever extent of mind trickery you do, you may say it is an illusion produced.


It is unclear what you are asking. An illusion is something that seems real but is not real.

If your 'illusion' can temporarily alter the way something looks, make your banana seem red, or make there seem to be two bananas, then calling it an illusion makes sense.

If your 'illusion' can make the banana seem to fly twice as far as I threw it, but once the illusion wears off, you see I only threw it 10 metres, not 20 metres, then fine, calling it an illusion is accurate.

If your 'illusion' can make the banana actually fly 20 metres instead of 10 then it's not an illusion. It's real.


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