Always Chaotic Evil
Always Chaotic Evil is a slang term that /tg/ has picked up from our frenemies over on TVTropes. The term originates from Dungeons & Dragons and specifically its early use of the mechanics of alignment. In the Monster Manual, creatures would always have their "alignment propensity", the specific alignment that the "average" member of their species would have, listed as part of their statblock.
It's mostly used as an easy placeholder term for the "typically villainous races" - orcs, goblinoids, gnolls, ogres, etc. A handy way to refer to the usual "chuck 'em at the PCs and let them hack 'em down" cannon fodder races.
The term has gotten a little unwelcome on /tg/ in modern years, as the basic idea that thinking humanoid races are somehow inherently evil and deserve only extermination is seen as being... well, a little too /pol/-friendly. That, and what's the point of roleplaying if you can't go against type (meaningfully, mind you)? These last years, focus has somewhat shifted to throwing people actively doing evil things (Slavers, Nazi's, etc...) as chaff to be exterminated to players instead of kobolds and their ilk. Additionally, Eberron has actually broken the trope entirely: alignment in that setting is canonically fluid by the rules given, so that evil-aligned clerics may worship/serve good-aligned deities, and vice versa (with a few exceptions; certain class-based restrictions, such as paladins having to be Lawful Good, remain).
It is telling that the grandfather of modern fantasy, J.R.R. Tolkien himself presented orcs as the servants of evil 'overlords', but was uncomfortable with the notion of 'born evil' or 'always evil' due to the theological implications of being born with an inherently evil soul. As a devout Catholic, the idea that Eru Iluvatar (his stand in for the Christian God) would deliberately create people who were inherently evil was contrary to his depiction as a purely good being, but Morgoth (read: Satan) could not create life himself, and Tolkien believed that making Orcs soulless would have caused them to become mere animals.
The solution that Tolkien used (though even then he was never wholly satisfied and settled only because the alternatives were worse) was that Orcs were effectively resurrectively immortal, and had been under the influence of Morgoth and later Sauron (the Evil Overlord of the setting) for thousands of years by the start of the story--and even then, as soon as Sauron's will vanished, so did their desire to fight, meaning that they were probably under some form of mind control at the time as well.
This sort of behavior can easily go too far in the hands of a sloppy writer. Morality in humans is at its roots an extension of the fact that we are social animals that work better together. Parents raise their children, protecting them when they are small and vunerable and teaching them how to do things so they don't have to figure out everything on their own and build on the knowledge of their forebearers. A tribe of humans pools its food so that those which are unlucky can get the calories they need to live and forage another day when they will be lucky and bring in a surplus. In an agrarian setting several farmers till the land and raise livestock which they give to the local blacksmith who forges iron tools so they can better till the land and produce more food per square meter and together they provide food, weapons and arms to a warrior who defends them from attack. Those are are just two basic arrangements of which a medieval society needs to operate, let alone a modern one. All of which is predicated on people getting along which we generally do more often than not. If everyone around you is liable to stab you in the back for momentary gain or for a larf as they are all dyed in the wool self centered sadistic sociopaths, the listed arrangements can't work. The lack of cooperation would prevent any such society they might dream of making from getting off the ground. The only rational thing for said creatures to do is to avoid others of their kind like the plague, unless of course they can mug them...and in the case of humans, subsequently die from a wide variety of circumstances (famine, crippling injuries leaving then unable to find food, etc.) which they would probably have avoided if they had just worked with others.
Standards & Examples
The usual standards for "entirely evil species" nowadays requires one or more of the following:
- Be reborn into that species or type of creature after a sufficient amount of evildoing. This is how it works for D&D for the most part: evil people die, and their souls are essentially tortured and/or warped by horrific powers to become the fiends of the Lower Planes (devils, demons, gehreleths, yugoloths, assorted others). The process used to create such beings is designed to utterly strip away every vestige of humanity remaining in a soul, basically "purify" the latent evil inside of it, and create something that is incapable of empathy as we would understand it. (Note that this absolutely does not mean that such beings might not turn stag on their alignment so much as make it extremely unlikely they would do so on their own; this was actually one of the interesting points in Planescape, and there is astonishingly a good-aligned mind-rape spell in Book of Exalted Deeds that can reverse the process, forcing an evil being to confront its nature and reemerge as a good being).
- Have biological requirements incompatible with peaceful coexistence. The best and first example of these are the undead who absolutely require feeding on living, sapient beings to survive. Among these the best two examples are ghouls (who must consume living flesh) and vampires (who must drink blood and/or lifeforce, depending on the setting). This is one of the biggest motives running through the World of Darkness vampire games: you are continually doing fucked-up stuff to just survive, and spend your time pitting your fleeting Humanity against the raving bloodlust of the Beast inside you (and this is all before you start sailing towards a moral event horizon due to vampiric politics demanding even worse crap from you). Shadowrun also has a big moral quandry here with their ghouls, who actually form a nation out in Africa and are always agitating for equal rights despite their diet.
- Constructed from certain dark/negative emotions or concepts. This is usually given as the reason why Frankenstein's Creature is violent and malicious: it is depicted in most media as having been made from the parts of convicted criminals, including the brain of an executed murderer, which reacts badly when other people see how fucked-up it looks and acts. Or take the Daemons of Warhammer; they are psychic entities made of emotions carried way too far; for example, "Bloodletters" are essentially endless anger given form.
- The creature is of such alien mentality and physiology that it is incompatible with human life as we know it. Good examples are things like the Orks and Tyranids of Warhammer 40,000, who are genetically driven to destroy and/or consume all other species.
Note that most games define good and evil through a human-survival morality, which denotes a fundamental respect for life (well, at least human life; we're pretty shitty toward other forms of life, to say nothing of how we treat our own kind). Blue And Orange Morality from TVTropes doesn't really apply where non-human creatures who are as far above us as we consider ourselves above animals may see us as the same kind of vermin or parasites we ourselves routinely destroy to preserve our own survival. Most such beings who do get to know humans advocate for them; the rest talk over/around us about dealing with certain things.
Also, the influence of a divine being trying to force a certain mode of behavior doesn't wash: evil can only exist where there is a choice between doing one thing or another - such as harming someone or not harming them - and actively choosing the evil course of action as the preferred one. This is why the drow don't get a fucking pass, kids. Yeah, they choose to serve Lloth, and yet they could always run away, rebel, join with Elistraee or some other deity, etc. Can Lloth make life short and horrible for such people? Sure as fuck she can. But if that person dies in a "state of grace", maintaining a Good alignment the entire time, they break free and get to go to the Upper Planes. In a way, it makes drow even more despicable, since unlike other beings who try to secure better positions for their damned souls, all the drow do is whatever their spiteful bitch-goddess Lloth tells them, then get to enjoy a shitty time in the Demonweb Pits being her fuck-puppet for eternity.
All that being said, Goblins and Orcs and the like are still sword and spell fodder, but nowadays the conflict is more likely to be cultural ("they want us off what they consider their land") or religious ("the Blood God demands Blood, and they think your little hamlet looks like it can supply a large quantity thereof"), and non-combatant Orcs are likely to be treated as well as any other enemy non-combatants.