Gelatinous Icosahedron

 It seems fitting, after the harpy, to focus on another creature of wing and feather, this time one of a more natural and less malevolent persuasion. I give you the hawk. We all know what hawks are, so there's no need to recapitulate that here, even though the monster entry in fact does describe what a hawk is. What is of note is that all hawks do double damage on their first attack if they surprise their targets. Two varieties are detailed, normal and giant. It is noted that normal hawks won't attack human-sized or larger targets unless they appear unable to defend themselves. (It seems extremely unlikely that they'd attack even halfling-size creatures unless for the same reasons or maybe in cases of desperate hunger.) Their stats, AC 8, 1/2 Hit Die, and 1-2 damage per attack, bear this out pretty soundly. Their movement rate is an impressive 480' (160'), though, and their Morale of 7 is decent. It's the giant hawk you might need to watch out for, especially if...

 Anyone who's played old school D&D is probably familiar with the potion of poison, one of the items which might be generated by random rolls on the magic item tables. Any potion found might be poison, up to 1 in 8 if only the Basic Rules were used, or a mere 2 in 100 when using the tables from the Expert Set. According to the item description, if any amount of the potion is swallowed, even a sip, the character consuming it must make a saving throw vs. poison or die.  I believe the potion of poison was meant to serve the purpose of risk, making players always a little bit apprehensive about any potions their characters might acquire during an adventure. I believe this in large part because no practical uses were even suggested for the potion of poison; it seemed to be included in the lists only as a "gotcha!" item. While uncertainty and risk are important parts of a good D&D session, it is always preferable to enable players to manage these for themselves, to make...

 I've always been a Classic D&D guy. It probably has a lot to do with the fact that my first exposure to any form of the game was the Moldvay Basic set. I wasn't aware AD&D was its own separate thing until I got a copy of the Player's Handbook. Since that day, I've harbored a deep fascination for the game, with all its baroque design, its dense and often unnecessarily verbose prose, its inelegant asymmetry, and its plethora of heavily footnoted charts and tables, but I've played in maybe one or two sessions and have never run the game myself.  I know many gamers see AD&D 1e as the pinnacle of D&D, sometimes with a corresponding disdain for the classic Moldvay and Mentzer iterations ("kiddie D&D" is the term used by those who have no interest in veiling their elitism). One prominent blogger in particular, who was once the foremost champion of B/X, now only extolls the perfect virtues of AD&D 1e. Much of this change of heart seems to ...

 Here's a monster that seems to be the product of a mashup between two very similar mythical creatures: the harpy. Mythological harpies are hybrids of women and birds who were traditionally associated with storm winds. Some early incarnations describe their human aspects as attractive, but mostly they were held to be quite repugnant. So far, it matches pretty closely with the D&D harpy. What it's missing is a song that can charm humans. That ability is traditionally associated with another mythical being, the siren. While sirens in later years are usually thought of as mermaid-like creatures with the lower bodies of fish, in their earlier incarnations they were described as having the faces of women, and the bodies, feet, and wings of birds. The D&D harpy is described more specifically than either, having the lower body of a giant eagle and the upper body and head of a hideous woman.  Stats-wise, harpies are pretty formidable opponents for Basic-level parties. Their AC...

 We've finished off the Gs, so let's start the Hs, with another PC-as-monster entry: the halfling. These entries in the B/X bestiary tend to be brief, and the halfling is no exception to that trend, weighing in at a mere four sentences plus the obligatory stat block. By the stats, halflings are not very threatening, having a mediocre AC of 7 (Is it leather? Is it a shield and a +1 Dex bonus? Who knows?), 1-1 HD, 90' (30') movement, damage by weapon, and Morale of 7. It's interesting to note they have by far the highest dungeon Number Appearing of any PC-as-monster type, at 3-18, well ahead of Veteran at 2-8, and are tied for wilderness Number Appearing with dwarves at 5-40. It is also noteworthy that their wilderness "lair" (i.e. village) explicitly disregards the standard rule of thumb of five times the listed number appearing (25-200 in this case) with an alternate number of 30-300. A village will have a leader of level 2-7 and a village guard of 5-20 in...