Now that we've got all the info about roleplaying games out of the way, something else you might be wondering: what exactly is Lovecraftian SF? Eldritch Skies is a science fiction RPG based on the works of H.P. Lovecraft and is set in the Cthulhu Mythos, which is a setting that he created, and which dozens of authors have been using for the last 70+ years. However, all interpretations of the Cthulhu Mythos are not the same. In the 1920s & 30s, when the original Mythos authors were writing, H.P. Lovecraft was not a horror author, or at least not solely a horror author. Like Clark Ashton Smith, his work spanned the genres of horror, dark fantasy, and science fiction. It's obvious that a story like "The Case of Charles Dexter Ward" is a horror story. It's equally clear that The Dreamquest of Unknown Kadath is fantasy, and both "At the Mountains of Madness" and "The Shadow Out of Time" are works of science fiction, and yet all of these stories are part of Lovecraft's Cthulhu Mythos.
From a modern standpoint, this diversity of genres is somewhat odd, but in the 1920s & 30s, the modern genres of Science Fiction, Fantasy, and Horror were all lumped under fantastic fiction, and they all appeared in the same magazines, such as Weird Tales, Astounding Stories, & Amazing Stories. Readers and authors of the 1920s & 30s clearly knew the difference between a horror story like "The Thing On The Doorstep" and a science fiction story like "The Shadow Out of Time". However, genre boundaries were far less rigid 80 years ago, and so there were many stories like "The Dreams if the Witch House" or "The Shadow Over Innsmouth" that were equal parts science fiction and horror. At the time, there were no bookstore regulations placing an anthology containing one story in the horror section and the other in the science fiction & fantasy section.
When most people today think of Lovecraft's Cthulhu Mythos, they think solely of horror,in large part because later mythos authors like August Derleth & Ramsey Campbell wrote their stories as horror and these later horror stories influenced the way that most readers see Lovecraft's Mythos. Eldritch Skies is a game that specifically looks at Lovecraft's Cthulhu Mythos as science fiction. To do so, all of later stories, written after Lovecraft's death are ignored. Instead, this is a game that focuses on the works of H.P. Lovecraft. Like the mythos Lovecraft created, Eldritch Skies contains elements of other work, such as Robert E. Howard's serpent people and Robert W. Chamber's The King In Yellow, which that Lovecraft included in his own stories. In short, this is the Cthulhu Mythos as Lovecraft saw it, but viewed as science fiction, rather than as horror or fantasy, and written from a modern perspective.
So, what does the term Lovecraftian SF mean? The most obvious answer is to be found in Lovecraft's most classic SF story - "At the Mountains of Madness". In this story, the mysteries of the Cthulhu Mythos are explained or at minimum are considered fully comprehensible. The “ancient aeons” of the other mythos stories become known geological epochs, the utterly inhuman aliens are (as one of the characters declares) "not evil things of their kind. They were the men of another age and another order of being". The alien beings like the elder ones, the great race of Yith, the mi-go, and others like them are not bizarre monsters, they are biological alien entities with thoughts and desires, and with civilizations that were filled with art, science, and technology.
Treating the Cthulhu Mythos as SF also means that even magic is explicable. As Walter Gilman discovered in "The Dreams in the Witch House", magical visions and also the apportations to distant places and perhaps even distant times or dimensions were shown to not be occult mysteries, but the deliberate uses of advanced science to manipulate the structure of space-time. In short, the creatures and magics of the Cthulhu Mythos are explicable natural phenomena and not unknowable mysteries. Along with this point of view comes the more general viewpoint common to almost all science fiction; knowledge is always superior to ignorance and that new knowledge can then be applied to solve problems.
In the stories "At the Mountains of Madness" and "The Shadow Out of Time" as well as in Eldritch Skies, the universe of the Cthulhu Mythos is a universe filled with both terrors and wonders, but it is also a universe where intelligent, civilized beings can have thriving advanced civilizations that last for aeons. Although even the greatest of these civilizations cannot destroy Cthulhu or any of the other Great Old Ones, some of civilizations can defeat and imprison even these terrible beings. This is not a universe where humanity or intelligent life is doomed, but it is also not one where intelligent beings automatically triumph over adversity. Of course, all this also means that the universe of Eldritch Skies is a perfect universe for characters to have all manner of exciting SF adventures.
Eldritch Skies is also a game about extrapolation. In Lovecraft's stories, the FBI dynamited Devil's Reef in 1928 and in 1931, a team of scientists discovered the ruins of the city of the elder ones in Antarctica. Eldritch Skies uses the fact that these and various other mythos mysteries have been known and studied as the basis for a timeline extending into the early 21st century. This is a timeline where various governments learned that alien beings visited and in fact still inhabit Earth. This is also a timeline where the various investigations into the various alien ruins have yielded numerous advances in science and technology. Discoveries about the Cthulhu Mythos have affected world history and the development of technology - to the point that humanity began traveling to the stars in the late 1990s and psychic powers are in common use.
Eldritch Skies also makes one other radical departure from most later mythos fiction. Most authors and readers of the last 50 years have seen the Cthulhu Mythos as one where humanity is not just doomed, but in imminent danger of extinction or horrific transformation. In many of these stories and RPGs, Great Cthulhu may rise at any moment and erase all civilization or even all of humanity. Many people consider this sort of bleak nihilism as an essential characteristic of the Cthulhu Mythos. However, looking at Lovecraft's own work shows that his own interpretation was different. In "The Shadow Out of Time", we have a description of the narrator's memories of talking with people and aliens from the past and the future, including an Australian physicist from the 26th century, a philosopher from the 50th century, and a magician from the 160th century. While the brief fragments of description of the 160th century looks fairly bleak, at least the next 3,000 years of human history seem devoid of returning Great Old Ones or the destruction of humanity. According to Lovecraft, humanity is clearly not in immediate danger.
One of the essential truths of Lovecraft's cosmology is that entropy and the other cosmic forces (as personified as the Other Gods and Great Old Ones) are far greater than any civilization or species, including humanity. Although humanity may be ultimately doomed to becoming extinct and eventually forgotten, this fate may not occur for tens of thousands or even hundreds of thousands of years. Lovecraft's cosmic horror is horror on a cosmic timescale, not the immediate horror of impending destruction.
However, the Cthulhu Mythos is also not an ultimately hopeful cosmos. There is no benevolent deity acting as the champion of humanity and humanity has no grand destiny to colonize or conquer the galaxy. Instead, we are merely one of hundreds or perhaps thousands of intelligent species throughout the galaxy who evolve, develop civilizations of various sorts, and then die off, leaving behind only weathered ruins and inscriptions in lost languages to mark their passing. In this universe, non-human species have all manner of exotic body plans and physiologies and there is nothing remotely special or impressive about the human form or the human mind. Ultimately, this is essentially the same view that modern geology and astrophysics has been revealing about the universe around us for the past century or so. Humanity is simply another intelligent species of many. Humanity is special and important to us because it is our species, but it is no more cosmically relevant than fruit flies, giraffes, or any of the many intelligent and non-intelligent alien species found throughout the galaxy.
While humanity is not particularly impressive, in Eldritch Skies, the universe as a whole is wondrous. Eldritch Skies is set in a universe far richer, stranger, and considerably more dangerous than our own. Swift and even instantaneous travel to other star systems is not only possible, but occasionally happens by accident. Also, there exist exotic hyperspatial dimensions, inhabited by strange and often dangerous creatures, as well as exceptionally powerful entities, such as the Other Gods and Great Old Ones, which have capabilities so far beyond our own. Humanity are like insects in comparison to the greatest of these beings. In Eldritch Skies, these beings are not actual deities, but simply beings of extreme power. Nevertheless, if someone is unfortunate enough to encounter one of these entities, they are unlikely to care or even notice this distinction.
As is true of all good science fiction, Eldritch Skies is most of all about humanity. It's a game where humanity faces great challenges, but, like several of Lovecraft's own protagonists, and most especially the renowned sorcerer Randolph Carter, humanity is learning the truth about the cosmos and making their place in it. Humanity is in the process of learning how to use the various natural and preternatural laws of the universe they live in to their advantage.
So, what is Eldritch Skies? It's a game about humanity on the threshold of the stars, where it is starting to explore the wonders and terrors of the cosmos. It is a game where the characters defend humanity against various terrible threats, including both malevolent aliens and equally dangerous humans. It is also a game where the characters will help humanity take its place in the cosmos alongside the other important species, such as the mi-go or the great race of Yith. In your hands, this game can be the story of the triumph of humanity over adversity or it can be the story the doom of humanity, not because this doom is inevitable or unavoidable, but because the cosmos is dangerous and sometimes there are no second chances for sufficiently serious mistakes.