In general appearance, Orcs start out as small, green rough-skinned humanoids with pointy ears, claws, fangs, and very long noses, averaging 45 inches (115 centimeters) tall. They notably possess only four digits on hands and feet. Some Orcs are bald while others have shaggy hair and facial hair is an uncommon trait. Some Orcs grow over time and become larger than the average human, while others remain about the size of a human pre-adolescent child. They often dress in little more than loincloths, though more resourceful ones manufacture primitive armor or clothing. Orcs typically carry crudely made or stolen weapons and are rarely unarmed.

Orcs have an excellent sense of smell, especially when it comes to prey. Indeed, their sense of smell plays a far greater role in their perception of the world around them than it does in humans. Their unusual sensitivity to ionized materials allows them easily to detect most metals but makes most forms of smoke or other hydrocarbon exhaust especially offensive to them. They possess excellent night vision but adapt poorly to sunlight or strong artificial lighting. Hence, they nearly always restrict their outside activities to night-time, preferring overcast and/or moonless nights. Their visual range and acuity appear to be quite like human, albeit with a sharp drop-off towards violet (around 450 nm) and is augmented by a layer of retro-reflective crystal behind their retinas-- much like other predators adapted for night hunting. Their ability to operate normally in deep darkness has proven to be a decisive tactical advantage, especially when coupled with their well-deserved reputation for extreme violence and hostility. Orcs are commonly found in cave systems (preferring stone, rather than earthen dug outs) and rely on raids and theft from lightly populated settlements to sustain themselves.

Orcs primarily haunt the frontier lands where humans do not have a strong presence (or no longer maintain such a presence). Further, Orcs have demonstrated a strong preference for tropical and sub-tropical environments. They do not adapt well to cold climates and appear to require living conditions similar to humans. They show no special immunity to diseases (except for food-borne illnesses) and offer no special resistance to existing human weaponry. Their internal physiology closely mirrors that of humans, with very similar, identifiable organs and recognizable metabolic processes. They are, however, noted for having rather high pain tolerances and capacity to operate under injury and blood loss conditions somewhat more severe than those tolerated by humans.

Orcs are uniquely all-male, and are regarded as “genetic parasites”, possessing the ability to breed with human females with the pregnancy virtually always resulting in Orc offspring (90%+) or miscarriage. A significant portion (5%) of captive women will die from severe anaphylaxis within a few hours of impregnation. Orcs also appear to lack any “standard of care” concept for captives, whose illnesses and injuries are ignored entirely. Regardless, women are high-value targets as captives for use as breeding stock until their eventual deaths (and presumed consumption) at the hands of their captors. Human men and children are normally killed and eaten immediately upon discovery. Further, pets and livestock are also frequent targets and Orcs will resort to hunting local fauna when other, easier options are not available.

Orcs will always avoid areas where larger human populations are present and clearly in control. All attempts at contact or communication have resulted in hostility. Such hostility appears to be a functionally universal element in their culture, to include extremely violent in-fighting. Analysis of their culture has shown that they do not appear to possess any specific concept of religion, politics, or government. Their culture is a very simple "rule of the strongest" hunter-gatherer system with an emphasis on scavenging and combat. There is little indication of sociological development beyond this point. Their language is similarly primitive consisting of a total vocabulary of less than a thousand words without formal grammatical structure or syntax.

While most Orcs are (inaccurately) described as thoughtless brutes, they are neither stupid nor careless, have demonstrated an ability to learn, and exhibit a level of cunning, cleverness and adaptability that clearly indicates both sentience and intelligence. Despite this, their technology does not appear to have progressed much beyond Neolithic levels of development in most cases. Repeated exposure to more advanced cultures and technologies has not prompted them to implement any significant changes to their own. This inability to adapt is a serious cultural weakness and is the most easily exploited means to maintain tactical and strategic advantages over them.

This should not be interpreted as Orcs lacking flexibility. Survival through scavenging means having sufficient intelligence to learn to use simple technologies when encountered. Risk aversion is also a prominent characteristic of scavengers; hence Orcs rely primarily on stealth, ambush, and overwhelming numbers wherever possible. They appear to live by the motto, "attack where your enemies are weak; run from your enemies where they are strong". Indeed, they appear to have no concept of bravery or courage and consistently demonstrate a clear preference for ambushes and traps over direct confrontations.

Despite their notorious reputation for extreme violence and the occasional appearance of truly dangerous members of their species, most people perceive Orcs as mere pests that need not be taken seriously. As a result, rookie hunters and the ill-prepared often end up being killed, seriously injured, captured, eaten and/or raped by Orcs. These events stand as a stark rebuttal to those who underestimate them. Additionally, some have made the mistake of sparing Orc young, which potentially allows them to develop into smarter, stronger adults who will hold deeply seated grudges indefinitely. Orcs have no concepts of gratitude or mercy; to expect reciprocal behavior from them is a serious (sometimes fatal) mistake.

To venture into an Orc warren has also proven to be a very hazardous course of action. In past battles, military forces have often decided to use thermobaric or “bunker busting” weapons to essentially bury entire hordes alive; pursuit of enemy forces into unknown underground terrain was considered an unacceptable risk. In at least one documented case, Orcs responded by moving into the sewers and drainage systems of a medium town, using the humans above as defense against such actions. The resulting military conflict proved to be brief, intense, difficult, and deadly-- the Orcs showed themselves to be well-prepared and determined defenders. Hunters and amateur adventures would be wise to acquaint themselves with these events before venturing underground to search for Orcs.

There exists a small segment of the Orc population (less than 6%) that become larger, stronger, smarter, and therefore much more dangerous:

Hobs (“Hob-Goblins”): A much taller (averaging 8 feet or 2.5 meters) and more physically powerful variant of Orcs that act as bodyguards for nests or wanderers from one nest to another. Hobs possess substantially greater strength and size than typical humans but are not considered sufficiently dangerous to prompt an escalated response unless present in significant numbers. Shamans: Orcs that have gained the ability to use "magic". While none have credibly demonstrated any actual supernatural or psychic powers of any kind, they typically lead their own nests and are intelligent enough to create and implement better-than-basic tactics, techniques, and strategies, maintaining rule through the appearance of superior and/or occult knowledge. The presence of Orc totems in and around an Orc nest are common indicators that a shaman is present. They are physically unremarkable when compared to other members of their species. The presence of a shaman, alone, does not normally warrant an escalated response but should prompt extra caution by those who encounter them. Riders: Orcs which have tamed and bred a large and previously unknown wolf species to be used as mounts and/or guards. Such Orcs are otherwise unremarkable, but only relatively successful hordes can afford the time and resources necessary to keep their wolves alive and trained, indicating a more dangerous and cohesive group than those commonly encountered. The presence of a tribe with riders is often sufficient to draw a response from local militias and law enforcement. Champions: This variant are regarded as “heroes” among the Orcs. Compared to Hobs, they are a significantly greater threat in terms of strength, endurance, fighting skill and equipment. They often somewhat lack in intelligence but are capable and cunning fighters that can give even well-equipped veteran hunters/adventurers trouble. Champions are dangerous enough to trigger formal government action in response (National Guard, etc.) as they often recruit other Orcs to build small armies. Lords: Considered to be "kings" among the Orcs. These Orcs are highly intelligent and have gained sufficient knowledge and experience to command large Orc hordes often containing other “special” Orcs. Like Champions, they are capable and dangerous enemies. Lords are considered high-value targets by both law enforcement and national intelligence services; significant efforts will be made to capture one alive for interrogation, if possible. Lords often master local human languages and are capable of near-human-level communication, making them rare specimens, indeed. Physically, they resemble Hobs. Paladins: Another highly intelligent, but very rare breed of Orc. Unlike all others of their species, they appear to devote themselves to some form of primitive religion, the details and ideology of which remain unclear. As a result, they exhibit fanatical behavior and typically inspire the same in other Orcs. They often possess significant real-world leadership and combat experience as well as a repertoire of weapons, fighting skills, equipment, and overall cunning, making them the most dangerous of their kind. Much like their Shaman counterparts, they are rumored to possess so-called “magical” abilities, although no credible demonstration of such abilities has ever been observed. The presence of a Paladin will draw a formal national-level military response at sufficient scale to ensure the complete eradication of a Paladin and his fanatical followers. This is typically combined with evacuation of local human populations and other efforts to protect the public. Physically, these are the largest members of their species, often reaching heights of 9 feet (2.8 meters).