Alzrius
The EN World kitten
See, now this is how you end something on a high note!
The Illithiad is hands-down the best book in the Monstrous Arcana line, and not just because of the excellent dad joke that's its title. No, mind flayers have long been one of the most iconic monsters in D&D, having premiered way back in Strategic review #1, then going mainstream in Supplement III: Eldritch Wizardry, and appearing in adventures as early as D1 Descent into the Depths of the Earth (which for some reason isn't available on DriveThruRPG, so I'm linking to the D1-2 compilation instead).
To my mind, illithids are perhaps the single monster most worthy of an ecology book like this, as I'm of the opinion that they're possibly the most iconic monster in all of D&D (even if dragons are, quite literally, the name of the game). There's a reason why Stranger Things never named any of their monsters "the beholder" after all. But what is it about mind flayers that makes them so impressive?
My guess is that it's a combination of factors, the big one being that they straddle the line between "unknowable alien monstrosities" and "villains of genius intellect." The former makes it clear that they're creatures with which no coexistence is possible; they can't be bought, bullied, reasoned, or negotiated with. But the latter makes it clear that they understand you just fine, and can go out of their way to bedevil you. In fact, their psionic powers means that they'll get in your head psychically before they get in your head physically and eat your brain, which makes for a profoundly disturbing method of execution. Beholders might disintegrate you, but these guys will tentacle-probe you in a way that makes the way little green men do it seem positively benign.
...and The Illithiad took that to new heights. Seriously, this book isn't just a repository of mind flayer lore, but it also expanded on it in a way that D&D is still making use of today. You know "ceremorphosis," the disturbing way that illithids reproduce, and which was featured in the trailer for Baldur's Gate 3? Yeah, that comes from here.
That's not the only disturbing new tidbit to be found in this book. It also reveals several new psionic powers that mind flayers have invented, among them a taste link power that they use to make other creatures – typically other mind flayers in "performance eating" ceremonies, but also captured humanoids – experience the taste of brains as they eat them. Heck, sometimes they use it on the creature whose brain they're eating! Some seriously disturbing stuff there; I love it.
One thing that this book introduced which didn't take, I should note, is the illithids' origin story. In what was the third attempt to say where these creatures come from – previously they'd had their "home planet" explored in Dragon #150 ("The Sunset World"), before The Astromundi Cluster would retcon that entirely, claiming that the Clusterspace crystal sphere was where illithids originated (the culmination, perhaps, of how Spelljammer had taken the Underdark-dwelling mind flayers and put them in space, much as it did with drow and beholders) – The Illithiad not only explicitly de-canonizes The Astromundi Cluster (ignoring "The Sunset World" completely), but instead says that mind flayers were human time travelers who tried to go to the beginning of time and ended up "Outside" (which was later made clear to be the Far Realm).
Ironically, this would itself be de-canonized later, though the time travel part would remain: D&D 3.5's Lords of Madness: The Book of Aberrations would say that illithids are actually from the far future, and when their empire fell they traveled back in time to the recent past, where they've been working to change the future so that their reign will never end (though I'm not quite sure what that says about the githyanki and githzerai; did they follow the illithids back through time before splitting into two camps or something?).
And that's just two of this book's points. There's also how much it leans into the illithids' use of psionics, which you might remember that I'm a big fan of. Naturally, these use the new psionics rules from Player's Option – Skills & Powers, which (as noted previously) are also in the Dark Sun Campaign Setting (Revised and Expanded Edition), though that world has no illithid presence at all, unless you count the Spellfire card game placing the Annulus (3rd/411) there, which seems odd since that magic item is originally from Temple, Tower & Tomb, which is a generic adventure, although Athas was invaded by githyanki in DSE2 Black Spine, which seems like a precursor to D&D Third Edition's "The Incursion" event in Dragon, Dungeon, and Polyhedron...
...wait, what was I talking about again?
Right! Mind flayers! So, another cool tidbit from The Illithiad that didn't survive this book was how they see in infravision all the time, which contributes to their hatred and fear of the undead. See, with no natural body heat, most undead are near-totally invisible to mind flayers; throw in being immune to psychic powers and having no (edible) brains, the undead are mind flayers' natural enemies. So naturally, the presence of creatures like alhoons (also known by the much cooler name "illithiliches") and vampire mind flayers scares illithids something fierce.
And if you're a Ravenloft aficionado, your ears likely perked up quite a bit there, because you know that vampire illithids are originally from RQ2 Thoughts of Darkness. But while it's almost impossible to escape Ravenloft, The Illithiad explicitly tells us that at least one vampire mind flayer did so, which means that those creatures (which, unlike illithiliches, are little more than ravenous beasts) can now be found anywhere. More trouble for your PCs!
I should also point out that The Illithiad was something of an indirect redemption of the Ravenloft domain of Bluetspur, which is where illithids in the Demiplane of Dread come from. While everyone knows that the darklords of the various domains all have curses that torment them, it was always kind of hard to define that in the context of Bluetspur's lord, the Illithid God-Brain; likewise for showing what a "horror version" of illithid society was like, compared to their "normal" culture.
That's where The Illithiad comes in. It was here that we were told that illithids eschewed arcane magic in favor of psionics (and, for a small few, divine worship of their gods Ilsensine and Maanzecorian, the latter of which died in Planescape's Dead Gods), with arcane practitioners being killed unless they fled and became outcasts. But in Bluetspur, the illithids not only practice magic, but practice biomancy and necromancy, engaging in activities that most mind flayers would find to be a perverse mockery of their cultural values.
And the God-Brain? Well, it makes no attempt to hide that it has its own wants and desires, the greatest of which is to be an ambulatory being, which is obviously impossible for it, so instead it absorbs the brains of various creatures – of all types – in order to assimilate their memories of their mobile existences. This is in stark contradiction to what The Illithiad tells us about elder brains, which is that while they do have distinct personalities, they go out of their way to hide this from the illithids they rule over. That's because illithids believe that each elder brain is a single gestalt consciousness, and that when their brains are added to it after death (and only theirs; the idea of adding a non-illithid brain to the elder brain would never occur to a "sane" mind flayer), they think they become part of that. In fact, the elder brain simply absorbs their knowledge and squelches their personality completely. So yeah, Bluetspur's God-Brain is clearly a deviant from illithid standards (and for all we know, that's what got it its own domain in the first place).
Really, all of that feels like it's just scratching the surface of what's here. Information about the illithids' written language, their stories about "The Adversary" (who kept their human personality even after undergoing ceremorphosis), new illithid tools and gear, a bestiary that compiles creatures like ulitharids and brain golems with new monsters like urophions and neothelids; there's just so much here! Don't even get me started on how illithid society as a whole has the goal of extinguishing suns; now that's the sort of lofty ambition your society of brain-eating monsters should have! It's no coincidence that this was the book that made me start to wonder if I should be picking up the Monstrous Arcana adventures; alas, I'm still looking for print copies of A Darkness Gathering, Masters of Eternal Night, and Dawn of the Overmind.
Though personally, I think there should have been an illithid lich who was trying to make friends with some cannibal zombies, since for all their differences, they're united in their love of brains.
Please note my use of affiliate links in this post.
The Illithiad is hands-down the best book in the Monstrous Arcana line, and not just because of the excellent dad joke that's its title. No, mind flayers have long been one of the most iconic monsters in D&D, having premiered way back in Strategic review #1, then going mainstream in Supplement III: Eldritch Wizardry, and appearing in adventures as early as D1 Descent into the Depths of the Earth (which for some reason isn't available on DriveThruRPG, so I'm linking to the D1-2 compilation instead).
To my mind, illithids are perhaps the single monster most worthy of an ecology book like this, as I'm of the opinion that they're possibly the most iconic monster in all of D&D (even if dragons are, quite literally, the name of the game). There's a reason why Stranger Things never named any of their monsters "the beholder" after all. But what is it about mind flayers that makes them so impressive?
My guess is that it's a combination of factors, the big one being that they straddle the line between "unknowable alien monstrosities" and "villains of genius intellect." The former makes it clear that they're creatures with which no coexistence is possible; they can't be bought, bullied, reasoned, or negotiated with. But the latter makes it clear that they understand you just fine, and can go out of their way to bedevil you. In fact, their psionic powers means that they'll get in your head psychically before they get in your head physically and eat your brain, which makes for a profoundly disturbing method of execution. Beholders might disintegrate you, but these guys will tentacle-probe you in a way that makes the way little green men do it seem positively benign.
...and The Illithiad took that to new heights. Seriously, this book isn't just a repository of mind flayer lore, but it also expanded on it in a way that D&D is still making use of today. You know "ceremorphosis," the disturbing way that illithids reproduce, and which was featured in the trailer for Baldur's Gate 3? Yeah, that comes from here.
That's not the only disturbing new tidbit to be found in this book. It also reveals several new psionic powers that mind flayers have invented, among them a taste link power that they use to make other creatures – typically other mind flayers in "performance eating" ceremonies, but also captured humanoids – experience the taste of brains as they eat them. Heck, sometimes they use it on the creature whose brain they're eating! Some seriously disturbing stuff there; I love it.
One thing that this book introduced which didn't take, I should note, is the illithids' origin story. In what was the third attempt to say where these creatures come from – previously they'd had their "home planet" explored in Dragon #150 ("The Sunset World"), before The Astromundi Cluster would retcon that entirely, claiming that the Clusterspace crystal sphere was where illithids originated (the culmination, perhaps, of how Spelljammer had taken the Underdark-dwelling mind flayers and put them in space, much as it did with drow and beholders) – The Illithiad not only explicitly de-canonizes The Astromundi Cluster (ignoring "The Sunset World" completely), but instead says that mind flayers were human time travelers who tried to go to the beginning of time and ended up "Outside" (which was later made clear to be the Far Realm).
Ironically, this would itself be de-canonized later, though the time travel part would remain: D&D 3.5's Lords of Madness: The Book of Aberrations would say that illithids are actually from the far future, and when their empire fell they traveled back in time to the recent past, where they've been working to change the future so that their reign will never end (though I'm not quite sure what that says about the githyanki and githzerai; did they follow the illithids back through time before splitting into two camps or something?).
And that's just two of this book's points. There's also how much it leans into the illithids' use of psionics, which you might remember that I'm a big fan of. Naturally, these use the new psionics rules from Player's Option – Skills & Powers, which (as noted previously) are also in the Dark Sun Campaign Setting (Revised and Expanded Edition), though that world has no illithid presence at all, unless you count the Spellfire card game placing the Annulus (3rd/411) there, which seems odd since that magic item is originally from Temple, Tower & Tomb, which is a generic adventure, although Athas was invaded by githyanki in DSE2 Black Spine, which seems like a precursor to D&D Third Edition's "The Incursion" event in Dragon, Dungeon, and Polyhedron...
...wait, what was I talking about again?
Right! Mind flayers! So, another cool tidbit from The Illithiad that didn't survive this book was how they see in infravision all the time, which contributes to their hatred and fear of the undead. See, with no natural body heat, most undead are near-totally invisible to mind flayers; throw in being immune to psychic powers and having no (edible) brains, the undead are mind flayers' natural enemies. So naturally, the presence of creatures like alhoons (also known by the much cooler name "illithiliches") and vampire mind flayers scares illithids something fierce.
And if you're a Ravenloft aficionado, your ears likely perked up quite a bit there, because you know that vampire illithids are originally from RQ2 Thoughts of Darkness. But while it's almost impossible to escape Ravenloft, The Illithiad explicitly tells us that at least one vampire mind flayer did so, which means that those creatures (which, unlike illithiliches, are little more than ravenous beasts) can now be found anywhere. More trouble for your PCs!
I should also point out that The Illithiad was something of an indirect redemption of the Ravenloft domain of Bluetspur, which is where illithids in the Demiplane of Dread come from. While everyone knows that the darklords of the various domains all have curses that torment them, it was always kind of hard to define that in the context of Bluetspur's lord, the Illithid God-Brain; likewise for showing what a "horror version" of illithid society was like, compared to their "normal" culture.
That's where The Illithiad comes in. It was here that we were told that illithids eschewed arcane magic in favor of psionics (and, for a small few, divine worship of their gods Ilsensine and Maanzecorian, the latter of which died in Planescape's Dead Gods), with arcane practitioners being killed unless they fled and became outcasts. But in Bluetspur, the illithids not only practice magic, but practice biomancy and necromancy, engaging in activities that most mind flayers would find to be a perverse mockery of their cultural values.
And the God-Brain? Well, it makes no attempt to hide that it has its own wants and desires, the greatest of which is to be an ambulatory being, which is obviously impossible for it, so instead it absorbs the brains of various creatures – of all types – in order to assimilate their memories of their mobile existences. This is in stark contradiction to what The Illithiad tells us about elder brains, which is that while they do have distinct personalities, they go out of their way to hide this from the illithids they rule over. That's because illithids believe that each elder brain is a single gestalt consciousness, and that when their brains are added to it after death (and only theirs; the idea of adding a non-illithid brain to the elder brain would never occur to a "sane" mind flayer), they think they become part of that. In fact, the elder brain simply absorbs their knowledge and squelches their personality completely. So yeah, Bluetspur's God-Brain is clearly a deviant from illithid standards (and for all we know, that's what got it its own domain in the first place).
Really, all of that feels like it's just scratching the surface of what's here. Information about the illithids' written language, their stories about "The Adversary" (who kept their human personality even after undergoing ceremorphosis), new illithid tools and gear, a bestiary that compiles creatures like ulitharids and brain golems with new monsters like urophions and neothelids; there's just so much here! Don't even get me started on how illithid society as a whole has the goal of extinguishing suns; now that's the sort of lofty ambition your society of brain-eating monsters should have! It's no coincidence that this was the book that made me start to wonder if I should be picking up the Monstrous Arcana adventures; alas, I'm still looking for print copies of A Darkness Gathering, Masters of Eternal Night, and Dawn of the Overmind.
Though personally, I think there should have been an illithid lich who was trying to make friends with some cannibal zombies, since for all their differences, they're united in their love of brains.
Please note my use of affiliate links in this post.
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