Gelatinous Icosahedron

 Here we have not only one of the most powerful monsters in the Expert Rules, but in the game as a whole, far surpassing dragons and giants, rivaled only by the giant roc. Of course, it's the mighty dragon turtle.  Conceptually, the dragon turtle is a magnificent creature. It's described as having the head, limbs, and tail of a dragon with the shell of a giant turtle. It lives in the deep sea, seldom surfacing but capable of wreaking terrible havoc when it does. It's so large it has been mistaken by sailors for a small island, presumably when it's just floating along in a deep doze, which is the only way you'd ever want to encounter one. Dragon turtles are known to rise up under ships, overturning them so they can devour the crew and passengers. Their lairs are in huge caverns at the bottoms of the deepest oceans, where they hoard treasures gathered from sunken ships. These things sound like the stuff of legends scarcely to be believed, and of sailors' most terr...

 There's a lot more to B/X dragons than just a standard stat block and a breath weapon, so here we are once again, to think about them some more. Every dragon in B/X features percentage chances of talking and of being asleep when encountered. "Talking" means the dragon can speak Dragon, Common, and cast magic-user spells. This ranges from a paltry 10% for white dragons, jumping up an additional 10% for each color, and then all the way to 100% for gold dragons. This seems to imply that most dragons can't even speak their own tongue, which is a bit weird. If they can talk, though, their power level takes a big jump with the use of spells. Even the lowly white dragon gets three 1st-level magic-user spells, and could make very potent use of such magics as ventriloquism , sleep , or charm person , should the creature be lucky enough to get them. If they end up with stuff like read magic , shield (practically useless to dragons, who already have better AC), or floating dis...

They're half the game's name, and there's a whole lot to unpack in their entry in the monsters chapter of the Basic Rules, so let's dive right into dragons! Everybody knows dragons, even those who have never read a fantasy story or played an RPG. "Dragons are a very old race of huge winged lizards." The opening sentence of the dragon entry in the Basic Rules is almost entirely unnecessary, except that they had to say something to get the ball rolling. Immediately after that, we get into the specifics of dragons as D&D conceives them, which may differ from any given incarnation of the monsters from folklore and literature. We're told they prefer to live far from human habitations, they're carnivores, egg-layers, have breath weapons, love treasure, and are willing to do almost anything to save their lives, including surrender. They are also Color Coded For Your Convenience, with the color of a dragon's hide indicating its alignment, habitat, bre...

 The doppleganger, from the Basic Set, is up now for the A to Z treatment. (I'm going to use the official D&D spelling of the creature's name instead of the proper German spelling doppelgänger , even though spellcheck keeps underlining it in red.) Though I've rarely used them, dopplegangers have always been one of the more fascinating monsters to me. The Basic Set does well not to describe their natural form in detail, nor to offer a picture of it, keeping it suitably mysterious in my mind. In fact, the only bits I take issue with are the final sentence of the monster description and a single word from a languages table earlier in the book. More on that later. The doppleganger is described as a man-sized, shape-changing creature that is intelligent and evil. It can take the form of any humanoid up to seven feet tall, and will attack that person. If possible, it tries to dispatch this target without the rest of the party knowing, so it can infiltrate the group and attack...

 Allow me to preface this post with the (probably needless) statement that I truly love B/X D&D. It was the edition which introduced me to the game, and still the one I consider the most perfect in its RAW form as well as the most customizable.  But it does have a few glaring flaws. They don't make it unplayable by any means, but they make certain elements perhaps less enjoyable than they might be (but see above about the ease of customization via house rules!) One of those flaws is the design of the fighter class relative to the other classes. In the rules as written, the fighter has three advantages over other classes: a d8 Hit Die, the ability to use any weapon, and the ability to wear any armor. You could add a fourth, better attack probabilities, but that doesn't kick in until 4th level, so for the first three levels, arguably some of the most fun to play through as well as the most vulnerable of a character's career, it doesn't count. Excepting Strength bonuse...

 Turning now to Arabian and Middle-Eastern folklore, we find the djinni... or more specifically, the lesser djinni, whose name implies the existence of a greater djinni, which does not appear in B/X canon. Presumably the greater form was slated to appear in the never-realized Companion Set. (It did eventually turn up in Frank Mentzer's Companion Rules.) A djinni (plural djinn ) is described as an air elemental taking the form of a tall human-like being surrounded by clouds. It is highly magical, making saving throws at twice its actual level and immune to non-magical attacks. In purely physical terms, the djinni is a formidable opponent, with a respectable Armor Class of 5 and 7+1 Hit Dice (averaging about 32-33 hp if rolled honestly.) Its pummeling attack with its fists causes 2-16 points of damage, or twice that of a character with a normal sword. Its walking movement rate is a rather ho-hum 90'(30') but it can take to the air at a breezy 240'(80'). Adventuring pa...

 It's definitely one of the weirdest creatures in the B/X bestiary. It's... the displacer beast, from the Expert Rules. The displacer beast is described as resembling a black panther with six legs and a pair of sharp-edged tentacles sprouting from its shoulders, which always appears to be three feet from its actual location. A quick internet search for the origin of the monster reveals that it was inspired by a beast called the coeurl from a science fiction story titled Black Destroyer by author A.E. van Vogt. (I had never heard of either the story or author before, but I may have to check them out now.) Despite this pedigree, the displacer beast proper is one of the handful of creatures considered to be the intellectual property of Wizards of the Coast, and retroclones include it only under alternate names.  The creature is quite robust, with an Armor Class of 4 and 6 Hit Dice. In addition to its very respectable AC, its displacement ability imposes a -2 penalty on all attack...

When it comes to fighting without weapons, D&D tends to go a bit insane. Besides often coming out overly fiddly and complex, subsystems for unarmed combat tend to mesh very poorly with the standard (armed) combat rules. Game designers, it seems, have tried to model a set of Hollywood fight tropes which don't fit well with the abstractions and assumptions of D&D combat. Consider, for instance, the ever-popular notion of knocking out an opponent with a single punch. In a game where clubs and maces can only whittle away the opponent's hit points, a rule allowing knockout punches produces results that are often counterintuitive, if not outright ridiculous.  I've made my own attempts on more than one occasion to construct a set of viable grappling/unarmed combat rules, but now I'm coming at it from a very different angle. The main problems with unarmed combat subsystems are A) treating armed and unarmed combat as fundamentally distinct from each other when in most re...

 Today's monster is the most powerful lycanthrope in the B/X rules as written, the devil swine from the Expert Set. Devil swine are described as lycanthropes who appear as either huge hogs or fat humans, who can switch between these forms freely at night but must remain in one or the other while the sun is up. I'm not aware of any specific reference from mythology or folklore for these monsters; if you know of any, please feel free to let me know in the comments! Aside from the unfortunate possibilities of making your players distrust every overweight NPC they encounter and making yourself a target for accusations of body shaming if you're not careful, devil swine are rather interesting monsters. They are meat-eaters, preferring human flesh, and live on the outskirts of human settlements, presumably for a convenient source of tasty humans, and especially those near swamps or forests, presumably so they have somewhere to flee should they be in danger of being discovered or s...