What is an alien?
Until now, when building characters for use in Edition 13 of the 4C System, the assumption has been that one is building a human being. You know, someone from the planet earth like you or me (well, you, at least), whose physiology is, or was at least originally, in line with that of other humans. The main exception to this is when one plays a product of humanity's knowledge, such as a robot.
Those characters who don't fall within this classification are considered alien beings. The complicated thing about generating an alien character is that their origin must include details about what makes them alien, on top of everything else about them that needs to be described. And with some aliens, this can be particularly complicated, depending on whatever it is that happens to mark them as an alien being.
And this starts with some basic questions.
Just What Are They?
The first thing to determine when designing an alien character is their basic nature. Alien beings can range from those physically and visually indistinguisable from your neighbors, to entities who we cannot even be perceive as living, to sanity-rending horrors whose mere presence may very well induce madness. Figuring out what kind of alien you wish to role-play includes choosing one of the following:
Humanlike aliens are those that are either completely human, or mechanically very close to that state of being. This kind of alien can represent offshoot species of humanity, or fictional species who appear completely human save for some abnormal characteristic such as pointy ears, weird forehead ridges, a particularly stout build, or perhaps green skin. Humanlike aliens may or may not have special powers.
Humanoid aliens are those sharing the same approximate shape as a human being, but have numerous special characteristics that are almost impossible to disguise. They may appear to be human-animal hybrids of some sort, like a satyr or mermaid, alien-human crossbreeds, particularly those of fae or demonic descent, or some other species that only shares the approximate dimensions of humankind.
Inhuman aliens are those who can't remotely be confused for a human being, and probably wouldn't want to be. This can include sentient, enhanced, or evolved animals, intelligent plants or fungi, distressingly large insectoid entities, strange masses of writhing bits whose function ignores the rational, or even oddities of biochemistry that are alive, but probably don't register as such to us until they act.
Inorganic aliens are the kind that are way, way off the beaten path. Rarely possessing anything remotely like familiar, biological processes, this form of alien can include mineral entities, fluid life forms, living masses of gases, ostensibly limitless founts of energy, or possibly even vivified artificial, seemingly manufactured objects. In the extreme, these can include sentient locations or phenomenon.
Where Are They From?
Once the kind of alien one wishes to build has been determined, players need to figure out where they come from. One's point of origin isn't quite as important as their physical characteristics, but is a vital portion of their background - unless the laws of physics are so different where they come from that they require special powers to survive here. Places of origin for alien characters can be one of the following:
Prime Earth: all kinds of beings that can be considered aliens come from our very own world. This can include strange offshoots of humanity living in secret societies previously hidden to ordinary man, mutant animals that are just as smart as (or smarter than) an ordinary person, or even inexplicable monstrosities living beneath the crust of the earth. Older media is replete with this sort of alien entity.
Other Earth: on the other hand, variant timelines are a great source of alien species. These can simply be humans native to adjacent timelines, universes where evolution went in a startlingly different direction than that which we know, or even aliens who, in addition to being from other worlds, are from a variant edition of their planet. This, of course, overlaps with the next place of origin somewhat.
Other World: while they are from the same universe as you or I, aliens from other worlds hail from a staggeringly different background than a world with a somewhat different history. This can cause the evolution of any number of extraterrestrial entities, ranging from the usual science fiction aliens with funny foreheads to awful terrors wrought in the crucible of a wildly divergent evolutionary progression.
Other Universe: while the previous assumes characters primarily originating in a space-time that obeys the same laws of physics familiar to humanity, all bets are off when pondering species evolved in other universes. Hailing from higher (or just incomprehensibly different) planes of existence, the creation of such alien species may or may not follow conventional causality or even common sense!
When Did They Originate?
Characters in Edition 13 of the 4C System are typically from the here and now, even if they're an alien scourge from beyond the stars. But not always! There's no end of temporal rifts, wacky contraptions, or mystical mishaps that can fling a body from their native place in the timestream into another era. And if one lacks the ability to traverse time by themselves, they're likely stuck here as a result.
Mechanically speaking, aside from the threat of being returned to one's native era by the use of spells such as banishment or exposure to the likes of temporal static, there isn't all that much of a difference between adventurers from the past, present, or future. A temporal displacement as part of a character's origin makes for a great story element, however, as well as an explanation for abnormal knowledge they may hold.
Furthermore, it's a great way to rationalize the existence of heretofore unknown posthuman civilizations, whether they can be described as timelost or technically haven't even been created yet! Belonging to an extinct or potential people can also mean less work for both the player and the Judge, as less effort needs to be spent explaining why this civilization hasn't been heard of previously in the game.
Who Are They?
Why Are They Here?
How Are They Represented?
Regardless of what the alien is and where they are from,
(Yes, we have no bananas, today)