Aside from the titular beast itself, orcs and goblins are perhaps the best known monsters associated with the Dungeons & Dragons game. Probably they are also the clearest link to the Lord of the Rings and Middle Earth, though less certain antecedents have been occasionally suggested. No doubt they have served as the foot soldiers and minions of an endless parade of dark lords and evil magicians in the decades since they were described in Monsters & Treasure. However, it was Chain Mail where they originally appeared for gaming purposes, and where a clear taxonomy was established. Therein kobolds and goblins are presented as equivalent, the only difference being that they have a reciprocal racial hatred for gnomes and dwarves, each respectively; above them are orcs, tellingly described as "nothing more than overgrown goblins" and in the Fantasy Reference Table equipped with bows. Both of these troop entries contain a note that stronger versions exist, in the case of goblins there are hobgoblins and for orcs there are "giant orcs". In ascending order of combat ability they can be listed as goblin, orc, hobgoblin, and giant orc. One significant difference between goblins and orcs is that the later are factional and will fight amongst themselves.
With Monsters & Treasure the same basic order is followed, though kobolds are shifted one class below goblins and “giant orcs” disappear, perhaps replaced by gnolls. Although the entries for kobolds, goblins and hobgoblins are very similar to one another, orcs are described in more detail and there is a table showing the probability of them being led and protected by a powerful fighting-man, magic-user, dragon, a small group of ogres, or even trolls. Interestingly, whilst in Chain Mail all of these monsters are always of chaotic alignment (p. 39), in Men & Magic orcs are also listed in the neutral column (p. 9). By the time of Strategic Review #6, and the emergence of the nine point alignment system, the thinking had changed so that goblins and kobolds are classed as lawful evil and orcs as chaotic evil. This pattern was continued in the Holmes edition of Dungeons & Dragons, and for the first time it is also noted that hobgoblins do not suffer any penalties when fighting in sunlight. Significantly, this tendency was ignored with the publication of the Monster Manual for Advanced Dungeons & Dragons, where orcs were listed with a lawful evil alignment, but are still noted to have a tendency for infighting. A comparison of basic statistics across editions can be downloaded here.
Obviously Tolkien and Middle Earth had a great influence on the depiction and development of orcs in the game, from Chain Mail onwards; goblins and hobgoblins mirror the definitions in the introduction to the Hobbit, the factionalism of orcs reflects events at the holdfast guarding Cirith Ungol, their collective dislike of sunlight and the eventual resistance of hobgoblins to its effects, even being armed with bows by default is suggestive of the uruks of Saruman. Visually, though, the orcs of Dungeons & Dragons, pig-headed and literally animalistic, diverge from the dominant aesthetic of Middle Earth. Furthermore, the Monster Manual artwork actively and significantly differentiates kobolds, goblins, orcs and hobgoblins from one another, leading eventually to the association of kobolds with dragons of all things. Notably the accompanying text no more supports the idea that kobolds have scales than it does that hobgoblins are equipped as pseudo-samurai. The sheer scale of variation and potential for confusion is probably most clearly demonstrated in an article published in Dragon #25, “Would the Real Orc Please Step Forward?” Diversity can be advantageous, but it is unusual for a monster to have such an indefinite appearance.
The artwork for the second edition of Advanced Dungeons & Dragons consciously compromised between the pig-headed orcs and the increasingly common depictions of monstrous grey-green humanoids; Doug Chaffee even went so far as to homogenise orcs and goblins for the front cover of Dragonspear Castle, which was an illustration also prominent in the Player’s Handbook. Furthermore, the arguably over detailed descriptions of humanoid "societies" in the second edition Monster Manual took its lead from B2 Keep on the Borderland, essentially treating them as primitive human tribes of evil disposition, with females and children to defend. Perhaps the origin of this view is an article by Roger Moore published in Dragon #44, "Fantasy Genetics I: Humanoid Races in Review", which suggests that kobolds, goblins, orcs and hobgoblins "represent a collateral branch of humanoid evolution." Certainly this seems to humanise and detract from the monstrosity of orcs and goblins, naturalising and reconciling them to a rational world that rejects the mythic underworld as sufficient explanation. Such socially organised monsters present an infamous conundrum for good aligned characters in dealing with non-combatants.
For the World of Silver Blade this subversion of the mythic monstrosity of orcs and goblins is far from satisfactory, but some sort of alternative explanation for their existence still seems necessary. Of course, Tolkien wrestled endlessly with their origin and nature without ever reaching any definite conclusion, even though the Silmarillion suggests that they are corrupted elves and the Lord of the Rings that they are bred in the black pits of Mordor and Isengard. The idea that orcs and goblins are bred by evil beings is intriguing and has some potentially horrific implications when one considers what the breeding stock might be. Still, the idea that they are bred like animals is perhaps an over rational interpretation, ignoring the inference that sorcery plays a significant role in the process. Although it may seem initially objectionable that orcs and goblins are created by magical means, it reinforces their existence as unnatural, and suggests them as a living parallel to the undead. Such a dislocation from the natural order of things capitalises on the fear of otherness that the mythic underworld lends to its monstrous denizens, evoking a sense of unknown evil in its distance from the human experience.
Somewhat fortuitously, there exists already an entire category of spells that can be leveraged in support of this conceptualisation of orcs and goblins. The various monster summoning spells cause creatures to appear from elsewhere in order to serve the caster for very short periods of time, but if instead they created the monsters permanently in a similar manner to the animate dead spell, then they become a ready explanation for how and why so many diverse monsters fill campaign worlds and their dungeons. In particular it explains why orcs and goblins feature so prominently as the foot soldiers of dark lords and evil magicians, magic creates monsters. Of course, it cannot be too easy for monsters to be created; broiling flesh pits would need to be prepared to provide living bodies for evil spirits to enter, in the manner of undead and demons, the evil dead put to new purpose, incidentally explaining why such creatures should be so aligned, and irredeemable. Compelling them to service might similarly be a difficult matter. No doubt this solution would neither be palatable or necessary for every campaign, but for the World of Silver Blade it preserves logically and satisfactorily the monstrous and unnatural nature of monsters.