Now we peek at the demihumans:
(as I have all of these in PDF, I'll be copying the relevant parts and making comments from there)
Original Dungeons & Dragons
Dwarves: Dwarves may opt only for the fighting class, and they may never progress beyond the 6th level (Myrmidon). Their advantages are: 1) they have a high level of magic resistance, and they thus add four levels when rolling saving throws (a 6th level dwarf equals a 10th level human);2) they are the only characters able to fully employ the +3 Magic War Hammer (explained in Volume II); 3) they note slanting passages, traps, shifting walls and new construction in underground settings; and 4) they are able to speak the languages of Gnomes, Kobolds and Goblins in addition to the usual tongues
Elves (these folks get tricky): Elves can begin as either Fighting-Men or Magic-Users and freely switch class whenever they choose, from adventure to adventure, but not during the course of a single game. Thus, they gain the benefits of both classes and may use both weaponry and spells. They may use magic armor and still act as Magic-Users. However, they may not progress beyond 4th level Fighting-Man (Hero) nor 8th level Magic-User (Warlock). Elves are more able to note secret and hidden doors. They also gain the advantages noted in the CHAINMAIL rules (I guess if you don't have the Chainmail rules you're crap outa luck for those advantages)when fighting certain fantastic creatures. Finally, Elves are able to speak the languages of Orcs, Hobgoblins, and Gnolls in addition to their own (Elvish) and the other usual tongues.
Halflings: Should any player wish to be one (I guess Raggi wasn't far off in making them a "throw away" class - heck, ACKS leaves the race out altogether), he will be limited to the Fighting-Men class as a halfling. Halflings cannot progress beyond the 4th level (Hero), but they will have magic-resistance equal to dwarves (add four levels for saving throws), and they will have deadly accuracy with missiles as detailed in CHAINMAIL.
Other Character Types: There is no reason that players cannot be allowed to play as virtually anything, provided they begin relatively weak and work up to the top, i.e., a player wishing to be a Dragon would have to begin as let us say, a "young" one and progress upwards in the usual manner, steps being predetermined by the campaign referee. (this goes far in showing just how "open" OD&D was meant to be)
Dwarves: Dwarfs are as fighters excepting that they are the only characters able to employ the +3 war hammer to its full potential. They are adept at evading large, clumsy enemies and suffer only half damage from such foes as giants and ogres (i'm guessing this comes from a later supplement or Chainmail?). Moreover, a dwarf makes all saving throws at four levels higher than his actual level (I would have read the original as applying only to magic attacks and spells, but I can see the justification for this way of reading it). He is, however, limited to the 6th level of advancement.
Dwarfs are expert miners and able to note any new construction, shifting walls, slopes, falling slabs, false floors and the like in dungeon stonework. They are also able to discern noises on a roll of 5-6 (on a six-sided die) when listening at doors.
Additionally, dwarfs are able to speak the language of gnomes, goblins and kobolds, in addition to the Common tongue and their own language.
Elves: Elves begin as either fighters or magic-users, but can change class between adventures as often as desired. An elf becomes dual-classed when he changes class for the first time, and may thereafter use both the weaponry of a fighter and the spells of a magic-user simultaneously.
The dual-classed character must maintain separate experience point totals for each of his classes, with all earned experience going toward his currently active class. He uses the more favorable game statistics of both classes during play, but cannot act as a magic-user while wearing non-magical armor.
Elves deal +1 hit point of damage when employing magic weapons and are able to move and fire a bow without penalty when on foot. They are nearly invisible in their gray-green cloaks, and can move almost silently. Additionally, they are able to locate secrets doors on a roll of 3-6 on a six-sided die when actively searching, or on a roll of 5-6 when merely passing by. They also discern noises on a roll of 5-6 when listening at doors and are immune to the paralyzing touch of ghouls.
They are, however, limited to 4th level as fighters and to 8th level as magic-users.
Elves are able to speak the languages of gnolls, hobgoblins, and orcs, as well as their own language, their alignment tongue, and Common.
Halflings: Halflings can choose to be fighters, but are limited to the 4th level. They have deadly accuracy with missiles, adding +1 to attack rolls, and discern noises on a roll of 5-6 on a six-sided die when listening at doors. Despite his diminutive stature, a halfling is highly resilient and makes all saving throws at four levels higher than his actual level. (at least there isn't a comment saying "should a player wish to be one")
Swords & Wizardry WhiteBox
The Dwarf: Dwarves tend to grow up in underground cities. As such, Dwarves easily take note of certain features of stonework: sloping corridors, moving walls, and traps made of stone (in particular: falling blocks, rigged ceilings, and tiny slits designed to release arrows, darts, or poison gas). There are no established rules or die roll for making use of these abilities; exactly what the Dwarf does or does not perceive is for the Referee to decide.
Dwarven Race Abilities
Character Advancement: The only character class available to Dwarves is that of the Fighter, and they are typically allowed to advance only as high as 6th level.
Weapon and Armor Restrictions: Like human Fighters, Dwarves have been trained in warfare and have no restrictions on the weapons or armor they may use.
Fighting Giants: Giants, ogres, and similar giant-type creatures such as trolls are not good at fighting dwarves, and only inflict half the normal damage against them. (i'm guessing this comes from a later supplement or Chainmail?)
Keen Detection: Dwarves are good at spotting traps, slanting passages, and construction while underground.
Saving Throw: Dwarves do not use magic and, as such, are somewhat immune to its effects; they receive a +4 bonus on saving throws vs. magic (whether or not the alternate “Saving Throw Matrix” is used). (see, I would interpret the save bonus this way too)
Languages: For campaigns that give each race its own dialect, Dwarves should be able to speak with gnomes, goblins, orcs, and kobolds.
The Elf: The Referee can interpret Elves in many different ways. Are they faerie-folk of Irish legend, the Vanir of Norse mythology, or perhaps something more akin to the Elves of Tolkien’s imagination?
As a baseline, most Elves are associated with magic as well as being skilled with the sword and bow. The Elven adventurer may choose, on any given day—perhaps when the moon rises—whether to use the capabilities of the Fighter or Magic-user. As a result, the Elf has two alternate advancement paths (experience points, hit dice, saving throws, “to-hit” bonuses, etc.) depending upon whether he donned steel that day or summoned up the power to cast spells.
Elves must use a spell book to prepare spells, just as a Magic-user. Spells disappear from his casting capability once they are cast, until prepared again.
Elven Race Abilities
Character Advancement: Elves may use either the Fighter or Magic-user class advancement charts, to be announced at the start of an adventure. They are typically allowed to progress only to 4th level as Fighters and 8th as Magicusers.
Weapon and Armor Restrictions: When an Elf adventures as a Magic-user, the character has the same weapon and armor limitations as a Magic-user. The exception to this would be magic armor, which may still be worn even when the Elf is acting as a Magic-user.
Hereditary Foes: Elves gain an extra +1 (“to-hit” or to damage) when fighting goblins, orcs, intelligent undead, and lycanthropes. Elves are also immune to paralysis caused by undead such as ghouls.
Keen Detection: Elves are good at spotting hidden and concealed doors (1-4 on a d6 when searching, 1-2 on a d6 if just passing by).
Languages: For campaigns that give each race its own dialect, Elves should be able to speak with gnolls, goblins, orcs, and hobgoblins.
The Halfling: Halflings are short, often stout, and live in shires, rustic communities that are usually remote from those of larger folk. A few of them have a mildly adventurous spirit, enough to venture forth for a while at least, exploring the world beyond the farms and fields of the local shire.
Halfling Race Abilities
Character Advancement: The only character class available to Halflings is that of the Fighter, and they are typically allowed to advance only as high as 4th level.
Weapon and Armor Restrictions: Like human Fighters, the Halfling has no weapon or armor restrictions.
Fighting Giants: Giants, ogres, and similar giant-type creatures such as trolls are not good at fighting small creatures such as halflings and dwarves, and only inflict half the normal damage against them.
Deadly Accuracy with Missiles: Halflings receive a +2 “to-hit” when firing missile weapons in combat.
Near Invisibility: When not engaged in combat, Halflings can be quite stealthy, making themselves hard to spot and moving in almost total silence.
Saving Throw: Halflings are somewhat immune to magic, and receive +4 on saving throws vs. magic (even if the “Saving Throw Matrix” is used).
Languages: For campaigns that give each race its own dialect, Halflings should be able to speak with creatures that fit the style of the Referee’s campaign.
Both Delving Deeper and Swords & Wizardry Whitebox flesh out the races with combat abilities "kinda" detailed in Chainmail. I know the Elves Secret Door Detection is iconic, I just dont see it in book 1 of OD&D (it could be there and I just dont see it). Interesting how DD goes for the low roll and S&W WB goes for the low roll.
I'd have to say that S&W WhiteBox is the better organized of the three so far, although DD does a decent job of explaining things and keeping it short.