Listed below are a number of ways that elements of one system can bleed into the other. The way conversions work depends on which system (and its resultant world-view) you adopt.

If you decide that OTE is primary, it means that the creatures of the Mythos are vulnerable to the tactics of Al Amarja's heavy hitters - the ancient technology of the Pharaohs and Glugs, the manipulations of the Throckmorton Device, the reality warping of the Cut Ups, and the multitude of techniques available to the Movers. Not to say that it would be easy for these groups to waste the Old Ones and their minions; but if they all worked together, they might be able to save Australia as a "human" enclave when the End Times arrive. It won't be easy, but humanity can (somewhat) counter or withstand the onslaught of the Outer Races.

If you decide CoC is primary, then Mythos technology always trumps human technology, Mythos magic kicks astral ass, and the best we can hope for is a renewal of our very temporary lease on this planet.

OTE Primary

Sir Arthur Compton

Compton is a powerful sorcerer, and he's aware of the Mythos. In fact, he could be considered a cultist; he has made "bargains" with Deep Ones and has even used the power of Great Cthulhu's sleeping mind for his own ends. However, he is not, in any sense, dedicated to Cthulhu or other Mythos creatures. He considers them a means to an end, and that end is, as always, his own power and pleasure. He does not anticipate the rise of R'lyeh for hundreds of years, so it does not concern him. If he believed the rise to be immanent, he would have to think long and hard about whether to fight for his current, comfortable existence, or to serve the Great Old Ones - permanently changing his perceptions and personality in the process. (Compton understands better than most what is required of the human servants of the Mythos.)

The Throckmorton Device

For uncounted eons, the Great Race of Yith have been "narrowcasting" their consciousness into the minds of other beings in order to possess them. The Throckmorton Device works differently, "broadcasting" the personality of its user to all similar minds within range - even stretching backwards in time.

There is a reason for this similarity; the device is based on Yithian technology that was scavenged by the Pharaohs and given to Angela Reyes by a device-dominated Quisling.

The device does not work on Mythos creatures, but the Great Race knew enough to keep Mythos magic and/or technology from interfering with their devices; this means the Throckmorton Device is similarly resistant. (If they chose to do so, however, the Great Race could easily prevent its full operation and could erase its effects from the time stream.)

If exposed to proof of the Mythos, Clyde Throckmorton might decide to put the persecution of homosexuals and poets on the back burner, while his minions concentrate on preventing the rise of R'lyeh or on eradicating Mythos creatures and their human minions. On the other hand, exposing Clyde to something that drives him mad would be bad. Very bad indeed.

The Terminal

The coral entities dwelling in the Terminal are aware of Yog-Sothoth, but do not serve it; instead, they are adept at navigating past it in the spaces between dimensions. Their plans to "untwist" dimensions in our reality will not prevent the rise of the Old Ones (who are comfortable in any number of dimensions) but they might provide an escape route to less hostile environs for a few representatives of humankind.

Tulpas and Sandmen

Tulpas naturally belong in the Dreamlands, where their plastic nature is a powerful help rather than a hindrance. However, once in a while, a tulpa will be tricked into slipping out through one of the rare physical gates to the Dreamlands. (The reason so many Tulpas reside in Al Amarja is that there is a particularly large gate in the center of Mount Ralsius - possibly related to the fissure described in "The Bliss of Death.") Once they emerge, the psychic static of the mass of waking humanity quickly erases the core of their personalities, leaving them blanks ready to be formatted by the expectations of the next passerby.

Sandmen are servants of Nyarlathotep, though they do not consciously know it. The Dreamlands god will only accept the most debased of sociopaths as servants, and once they have been inducted into his cult they are given the unusual powers of the Sandmen. However, the price of their initiation is the surrender of their knowledge of the cult. They simply forget how they came to be Sandmen, confabulating memories of childhood "awakenings" instead. Their only memories of dedicating themselves to Nyarlathotep are fragmentary recollections of degradation and torture at the hands of their senior Sandmen - which explains the culture of violence in which these loners live.

When it is time to induct a promising psychotic, the loathsome deity will allow one (or several) Sandmen to remember who they really serve. The inductee is kidnapped and initiated; and then they all forget again. Only once a year, on a secret feast day of Nyarlathotep, do all the Sandmen remember their true bond and nature. On that day, they gather for ceremonies.

The reason Nyarlathotep creates Sandmen is in order to disseminate Mythos dreams to humanity. Sensitive sleepers can be reached with horrid visions of Mythos significance; Sandmen are guided to these dreamers in order to imprint their nightmares on Dreamweb, which makes the nightmares available to those who are not psychically sensitive.

The Movers

Some Mover cells (notably the Hermetics) are aware of the Mythos. Others (the Dionysus and Gladstein cells) are unaware of the Mythos - but have been infiltrated by fanatic cultists. If Cell Z exists, it might be a highly secretive anti-Mythos force, willing to use any means necessary (no matter how unethical) to protect unwitting humanity.

The Pharaohs and the Glugs

Glugs are, indeed, the "real" humanity. They evolved around 1 million BC, largely free of Mythos interference. They were not noticed by Mythos entities until about 750,000 BC. At that time, Cthulhu was beginning to recover from the damage that the fall of R'lyeh had inflicted upon it. The Eight Kindly Sages came into contact with the sleeping psychic juggernaut, and were warped by the process into the Eight Evil Sages. They developed the Pharaohs, the Aphids and a slave-warrior race (known as "humanity") in order to dominate the world and pave the way for the return of Cthulhu. After a lengthy struggle, the Glugs were able to cause a widespread revolt among the slave warriors. While the Pharaohs were distracted, trying to keep the ravening humans under control, the Glugs killed the Eight Sages. However, neither Glug nor Pharaoh was able to restrain the warriors who were going utterly bonkers. The dark Age of Humanity descended, and it goes on to this day.

At this stage, neither the Glugs nor the Pharaohs are terribly hot on the idea of the return of the Great Old Ones. The Pharaohs have gotten quite used to the idea that they are the rightful owners of Earth. They have a great deal of knowledge on how to cope with Mythos manifestations, and they aren't afraid to use it if they have to. (In fact, the Neutralizers may simply be one of their better-deluded dupe groups.) However, they have a fine appreciation of what the greater Mythos races can do, and are therefore cautious to use expendable humans to do anything that might annoy them.

The Glugs have been bracing themselves for the return of the Great Old Ones for the past 750,000 years or so. Of all the branches of humanity, the Glugs are by far the best equipped to deal with Mythos threats. However, keeping their eye on the ball in the long term has cost them a lot; for one thing, their planet is overrun with kill-crazy mutants (like you and me). For another thing, the Pharaohs would certainly want to wipe them out if they found out there were Glug survivors. (Monique D'Aubainne knows about the Glugs, and she's keeping this knowledge for when she needs something special from the Pharaohs.) Since humanity was bred as slaves (and sacrifices) for Mythos beings, we are much more susceptible to their powers than the Glugs are.

The Kergillians

The Kergillians are actually Mi-Go. Long ago the Mi-Go developed the processes necessary to surgically transform themselves into a form that can parasitize human minds and bodies. They simply saw little need to do so. Now, however, some event has made the fungi from Yuggoth decide they need to take control of humanity. Perhaps they are involved in some interstellar conflict that simultaneously prevents them from conquering Earth outright and requires them to mine more of the rare minerals in which Earth is so rich. Maybe they want to get as many goodies from Earth as they can before the rise of R'lyeh. (The fact that they're accelerating their projects is probably excellent cause for alarm on that front.) Or maybe it's simply a big experiment for unguessable, alien ends. Whatever the case may be, the Mi-Go are taking their time - but they're coming.

The Cut-Ups

The desire to bust all of humanity down to the rank of "sacrifice" while Cthulhu and his minions romp across reality is possibly the ultimate in Control addiction. The Cut-Ups have tangled with Mythos cultists in the past (though only Dr. What has ever seen an actual creature of the Mythos) but they are unaware of the real importance of these conflicts. The cultists have done an excellent job of distracting the Cut-Ups into attacking other conspiracies, while the cults proceed unmolested.

The only piece of human technology feared (if such a word can properly apply to beings so alien) by Mythos creatures is the Cut- Up Device.

COC Primary

The Movers

The Movers are, in fact, a big front for Mythos activity. Almost no Movers know this, however; a few Vornites suspect it, and a few Hermetics fear it. Cell Z is dedicated to the destruction of the Mythos, and they think they're in charge; in fact, they never accomplish anything significant, because they're being manipulated by the real ruling cell. (The true master cell has no name and doesn't need one, but we'll call it "Cell C" for convenience.) The whole purpose of the Cell Z ruse is (1) to recruit enemies of the Mythos into a power structure where they can easily be fooled and muzzled and (2) to protect Cell C from any competent Mythos investigators. Any such investigators are more likely to run across Cell Z and believe that the Movers are on their side than to discover the core cult of Cell C.

Cell C can't wait for the rise of R'lyeh, as they plan to be right on top of the world, robbing and raping and rampaging with Great Cthulhu and the Star-Spawn, proving that human beings can be as unconscionable as anything else in the universe.

The LeThuys Mr. LeThuy hasn't heard of the Mythos, but if he did he would wet his pants in glee. They're exactly the kind of outfit he'd like to see inherit the Earth.

The Glugs and Pharaohs

For a full explanation, see the "OTE Primary" section, above. Now make a few key changes.

(1) The Pharaohs were created to create conditions conducive to Mythos invasion and domination. They've been fairly successful, and continue to be. Their rivalry with the Movers is seen by the leaders of both camps as a necessary deception to keep bloodthirsty mutant humans motivated by conflict.

(2) The Glugs' confidence in their ability to resist and repel Mythos creatures is misplaced. They can hold their own when the stars are wrong, but as things get more and more conducive to Cthulhu and his ilk, their techniques will become less effective.

The Throckmorton Device

Things are as explained under "OTE Primary." However, the domination of humankind by the Throckmorton Device is timed to occur only a hundred or so years before the rise of R'lyeh. That means that instead of having to conquer a vital, thriving and diverse humankind, the Old Ones will have only a homogenous mass of complacent nobrows whose "enemies" had their hash settled long ago.

Perhaps this is just a coincidence... or perhaps it's a particularly devious plot by an outer power. (No cultist would come up with this, because the device would prevent said cultist from being devout to the Mythos; thus, if the device triumphs, no humans will survive to serve Cthulhu in the new world disorder.) (Well, all right, it's dicey whether any will in any event; but the cultists believe they'll be rewarded for loyalty, for some reason.)

The Terminal Do you believe a bunch of smart corals could travel between dimensions while avoiding Yog-Sothoth? I didn't think so either. Sure, they don't broadcast their affiliation, but what exactly do you think the phrase "In order to make this dimension comfortable, they are planning to 'untwist' two spatial dimensions from their sub-atomic tangle" (Over the Edge page 86) implies? Read page 126 in the Call of Cthulhu rules where it says "Yog-Sothoth dwells in the interstices between the planes which compose the universe." Compare and contrast...

Sir Arthur Compton Arthur and his gang of icky followers can't wait for R'lyeh to rise so they can get their sick ya-yas out in ways that haven't even been invented on this planet yet.

The Cut-Ups

Ah, the ultimate irony; the ultimate cruelty. This brave, altruistic band has dedicated themselves to the practice, principle and provision of chaos. However, they don't realize the real chaos they serve is of the crawling variety.

That's right; the ultimate source of the Cut-Ups' weird abilities is none other than Nyarlathotep. Apparently one of his thousand forms is none other than Chaos Boys Headquarters.

Note that no Cut-Up will ever voluntarily believe that their entire organization is being manipulated by some unearthly entity from beyond the beyond. Nyarlathotep has taken great care to cover his tracks; in fact, there is very little chance of the Crawling Chaos ever being connected to the Cut-Ups, except possibly by an exceptional sorcerer who studied the source of C.A. Radford or Pere Brinker's powers. No, Nyarlathotep is very protective of his little joke; the Cut-Ups will only learn what their true role was after they have been used to eradicate humanity.

Call Amarja Of Cthulhu: Introduction