But the victory of the Elves was dear-bought. For those of Ossiriand were light-armed, and no match for the Orcs, who were shod with iron and iron-shielded and bore great spears with broad blades...
J.R.R. Tolkien, The Silmarillion
Orcs, shod with iron and iron-shielded.
And the Eagles of the Mountains went far and wide, and they saw many things: the gathering of wolves and the mustering of Orcs; and the Nine Riders going hither and thither in the lands; and they heard news of the escape of Gollum.J.R.R. Tolkien, The Fellowship of the Ring
And as they rode rumour came of war in the North. Lone men, riding wild, brought word of foes assailing their east-borders, of orc-hosts marching in the Wold of Rohan.J.R.R. Tolkien, The Return of the King
And they march.
In Tolkien's corpus, orcs are soldiers, unnatural weapons of war, twisted by Melkor from Elves. Their nature is reflected in the language Tolkien chooses to describe their actions. Orcs muster and march. They invade and assault. They appear shod with iron and iron-shielded, bearing great spears with broad blades. And they gather not in tribes or clans but in companies, in bands, and in hosts. They are not savages, primitives, barbarians. They are soldiers.
There are "savages" in The Lord of the Rings -- "the wild men" -- but they are very unlike the orcs.
So great a power and royalty was revealed in Aragorn, as he stood there alone above the ruined gates before the host of his enemies, that many of the wild men paused, and looked back over their shoulders to the valley, and some looked up doubtfully at the sky. But the Orcs laughed with loud voices; and a hail of darts and arrows whistled over the wall, as Aragorn leaped down.J.R.R. Tolkien, The Two Towers
Even in speech orcs are presented differently from "wild men." When Ghân-buri-Ghân, headman of the wild men speaks in The Return of the King, he does so haltingly, using nouns without determiners and verbs without inflection, and his speech often ellipses words that would normally be included in actual speech. His language is patterned to suggest barbarism. Orcs, in contrast, speak with the usual complement of determiners and verbal morphemes. The speech of orcs is different from the speech of hobbits and "civilized" men in the tales, certainly -- but it is represented with dialect forms, not with a caricature of "broken English."
Given Tolkien's academic specialty, it's hard to imagine any of this is accidental. Orcs are associated with war and industry -- mining, black smoke, and iron. They are not native savages living in tribes in the wilderness of Middle Earth.
Orcs in Dungeons and Dragons
In Dungeons and Dragons, the barbarian or savage orc predominates. So much so that it is often simply taken for granted. Do evil wizards use orcs as soldiers and guards? Sure. But orcs live in tribes in D&D (a fact established as early as OD&D's Monsters and Treasure and repeated throughout the AD&D line). That isn't to say that there are no traces of Tolkien's orcs in the early D&D books -- orc mercenaries remain on hireling lists, and even into 2nd edition, orcs remain Lawful Evil. But orcs live in tribes, and are natural beings, not unnatural creations of evil. And by 3rd edition (at the latest), the barbarian orc is firmly entrenched, a fact reflected in their shift to Chaotic Evil alignment and association with the Barbarian class. Orcs (and other humanoids) in D&D in general are presented as natural savages, not the unnatural footsoldiers of a dark god.
...and other roleplaying games
What about other fantasy RPGs? Off the top of my head, I know that orcs follow the savage/barbarian/primitive model in The Fantasy Trip (where the default assumption is that they're descendants of neanderthal-like peoples!). Dragon Warriors, in contrast, clearly positions orcs as the archetypal "henchthings of evil." In The Burning Wheel, orcs also hew somewhat closer to Tolkien, an unsurprising fact given that similar things can be said of the game's elves and dwarves. Warhammer puts a characteristic twist on them, giving us armies of supernaturally tough hooligans. Other games (such as, I believe, Runequest) do away with orcs completely, replacing them with another race of humanoid enemies.
I'm fond of the orc that marches, the orc that is a soldier, the orc that counts himself a member of a company, not a tribe. There's nothing intrinsically wrong with departing from Tolkien's take on orcs, of course, but I think it provides an interesting alternative to the dominance of the barbarian orc. I like to see proactive orcs invading and capturing territory as soldiers, raiding dungeons for weapons to use in their master's war against mankind, planning raids rather than berserking, and stealing silently under cover of darkness into position to strike at the forces of good.
Now the Orcs that multiplied in the darkness of the earth grew strong and fell, and their dark lord filled them with a lust of rain and death; and they issued from Angband's gates under the clouds that Morgoth sent forth, and passed silently into the highlands of the north.
J.R.R. Tolkien, The Silmarillion
How about you?