Infravision—Another Example of Gary’s Cunning Awesomeness?

So I might be coming a little late to this party (having played D&D and AD&D for about 25 years before switching to 3rd edition and its spawn) but I recently discovered something very cool about infravision…


The 1st edition Dungeon Master’s Guide (perhaps the greatest gaming book of all time) describes infravision as “the ability to see light waves in the infrared spectrum.”

What I recently discovered is that “infra” is the latin word for “below”. So, infravision literally means “below vision”. Given most early adventures took place in subterranean dungeons I think this is another example of Gary’s love of word play. Of course, I could be seeing a connection here where none really exists, but I prefer to think Gary knew exactly what he was doing.

Sadly, with the advent of 3rd edition infravision become darkvision. At the time I always wondered about this change as it seemed more than a little pointless. I now can only assume this is because the designers thought more adventures would take place outside in the dark and therefore infravision was a dated term.

What do you think? Was Gary being cunning? Or is the name just lucky happen-stance? Let me know, in the comments below!

And—if you share my love of word play, why not check out my new book, Cool Words for Gamers!





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Creighton is the publisher at Raging Swan Press and the designer of the award winning adventure Madness at Gardmore Abbey. He has designed many critically acclaimed modules such as Retribution and Shadowed Keep on the Borderlands and worked with Wizards of the Coast, Paizo, Expeditious Retreat Press, Rite Publishing and Kobold Press.

19 thoughts on “Infravision—Another Example of Gary’s Cunning Awesomeness?”

  1. I always thought that was shorthand for “infrared vision” which is a very specific wavelength of light most commonly associated with heat. Not sure there was any clever wordplay at all.

  2. Nice idea, but I think the use of the word “Infra” is more likely because the power allowed sight using light waves with a frequency “below”the range of normal human ability. In fact, I think I might have read that somewhere in the 1e DMG. In the same way, “ultra” vision is sight using light waves with a frequency “above” the range of normal humans.

    That’s the way I understood it anyway.

  3. I see a place for both infravision (infrared sensitive vision) and darkvision (low light vision). At the risk of bringing in too much realism, infravision would be vision sensitive to infrared light (heat) and creatures with this ability would not necessarily see everything in the dark; e.g. the undead. Creatures with darkvision would see better in darkness than creatures with “normal” vision, but could not see in pitch darkness (unlike with infravision); also darkvision would only see black and white (as color-sensitive cones in the eye require more light to activate).

  4. I believe that the idea for infravision came from one of the Appendix N authors. I want to say Poul Anderson, but I am not 100% sure. I was expecting to hear you say that the genius of infravision is that proximity to a torch spoils it (DM does not need to track what can be seen with two types of vision) and that it doesn’t reveal everything (you cannot, for example, read with infravision).

  5. Oh, and as others have noted, that infravision is explicitly vision in the infrared range (and ultravision is in the ultraviolet range), is made clear in the 1e DMG.

  6. All good and true – speaking as a Physics Teacher and a LOOONG time D&D player and DM I can speak with some authority on the Infrared part of the discussion and speculate on the Infravision too. ‘Infra’ does in fact mean ‘below’ and Ultra ‘above’ (the WW2 allied codes gained from hacking the Nazi codes were called ‘Ultra’ because they were above top secret). in this case the above and below refers to above and below the frequencies of light at each end of the visible spectrum. There is equivalent terminology in Sound with Ultra Sound being ‘frequencies above human hearing’ (so more than about 20-25000Hz; bats, Dolphins and the like, as well as medical scanners and the broadband signal on normal telephone lines) and Infrasound (frequencies below human hearing, so less than 10-20Hz, elephants, giraffe, whales use these frequencies as well as audible ones, and we use infrasound in the Earth’s crust to study Earthquakes and plate tectonics). It’s my guess old Gary knew all about this.
    One thing that’s important to note is that ‘Infrared’ and ‘Ultra Violet’ are not specific wavelengths but regions of a whole range of wavelengths each range much bigger than the visible spectrum. Some animals can see beyond visible red and into the near-infrared (cats and dogs I think) so it’s not unreasonable to suggest other races can see into this range as well. All well and good, they just see ore.
    Where this gets interesting is that everything emits some kind of electromagnetic radiation as a result of their heat, although the cooler they are, the lower this energy is. As they get hotter the higher the frequency (energy) of the light they emit; imagine heating a nail. It starts off cold and emitting a little IR radiation. We can’t see this so we only see the reflection of whatever ambient light the nail doesn’t absorb (which makes it look grey). As it gets hotter, the range of frequencies of light emitted by it gets higher, so it glows cherry red, then orange and eventually white as it emits most of the frequencies in the visible spectrum and our eyes register this combination as white.
    SO in D&D (sorry to ramble…) we can see that IR is a whole range of different invisible colours, so an elf would see all the colours we do plus a load more in the IR spectrum. When underground and away from bright light sources they would then be able to see the lower IR light level emitted by objects depending on their heat (and the reflected heat from the observer), in the same way we can see the stars away from street lights. So the elf can see the structures underground due to the slight difference in emitted and reflected heat. Depending on whether magic adds an extra little bit of heat to an objects then it only remains to decide whether undead are the same temperature as corpses and therefore appear different from them… Ultravision is a lot different and I haven’t really worked out yet how that would work…

  7. I think the change was a simplification. Infravision dealt with infrared and heat and all that jazz. I can’t count the number of conversations (and arguments) about whether such and who would be able to see the whosit whatnot because it was the same temperature as the ambient air or not. In the newer versions of D&D darkvision just meant the ability to see in the dark. It’s not tied to anything remotely scientific. You can just see in the dark. Up to a certain range anyway.

    I actually approved heartily of this change. Keeping track of infravision, ultravision, and / or heat vision was a pain the the ascot.

  8. Infra vision was seeing light waves below normal human vision, and even though it was started that hiding worked against it, the concept was difficult for people to match with science, given that more people are exposed to night vision and know you can’t really”hide”from it. To clear up the issue, they just changed its name so as not to imply you are seeing heat, but are seeing in darkness.

  9. I think the main reason it was changed to darkvision is that most people imagine heat vision when they hear infravision, where bodies light up in shades of yellow, red and purple, against a cold blue background, and the designers did not want predator style PCs running round the place.

  10. Infrared vision would be nearly worthless in a subterrainian setting, where almost everything would be the same temperature. Sure, you could see living creatures, whose bodies hadn’t adapted to hide their body heat. But it would be worthless for something so mundane as crossing broken terrain.

  11. In 1e there are two types of Infravision.

    Standard (Player character) and Monster.

    Standard is a passive heat vision (think predator) that actually sees the heat signatures of objects. This ability usually extends to 60 feet

    Monster infravision actually projects infrared light in a manner of an invisible flashlight (think generation 1 nightvision) and extends to 90 feet. Meaning that monsters can actually see in the absence of light as they emit their own light.

    Also note that monster infravision shows up as glowing red eyes to standard infravision……..

    Source DMG 59

    1. Also player infravision is definitely predator style heat vision in 1e, as it explicitly states that PCs can track the footprints of very cold or warm (and uses humans as an example) with infravision however they fade in 2 rounds.

      Source DMG 59

      1. This is further confirmed when describing that normal scrolls cannot be read when using infravision. It’s the reason why Menzoberrenzan has a small amount of visible light around the city, primarily near the areas devoted to the temples and academy

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