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.
It is telling that the "father" 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. 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 cause it to self-destruct.
The usual standard for "Entirely evil species" nowadays requires they be reborn into that race after a sufficient amount of Evildoing (for example, Devils that recruit from those sent to Hell), have biological requirements incompatible with peaceful coexistence (e.g., vampires who are required to kill living sentient beings in order to survive), they be directly "Made of Evil" (e.g., creatures made purely from the emotion of Hate or Greed), that they be "biologically evil" in a way that requires them to be either stupidly violent or part of a hive-mind (e.g., the Orks and Tyranids in Warhammer 40,000), or have a form of morality that is completely divorced from human understanding.
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.
See Also
- Detect Evil
- Demon, which depending on gameline and/or setting may or may not qualify
- Orc, for the original "Always Chaotic Evil" race
- Baatezu, for a fairly standard case of "Recruited and Recreated from Already Evil People"
- The Orc Baby Dilemma