Realms of Cthulhu is a complete role-playing game from Reality Blurs Publications which uses Pinnacle's Savage Worlds resolution system. Savage Worlds has become popular enough that many role-playing pdf publishers feel the need to publish Savage Worlds versions of their games and supplements. Reality Blurs carries licenses for both Savage Worlds and Chaosium Incorporated, so it was only a matter of time before they produced their version of an RPG based on H.P. Lovecraft's Cthulhu Mythos.
The Realms of Cthulhu role-playing game is ambitious, because it's actually four games in one. While the Shadows of Cthulhu offers a "pulp" and "purist" version of Lovecraftian horror, Realms of Cthulhu offers 4 different styles of play: Heroic Horror, Slippery Slope, Dangerous Action, and Dark Spiral. Each of these styles comes with special house rules to evoke the feel you want.
Gamemasters should have plenty of options for tailoring their campaign to the tastes of their playing group. That's particularly important in a Cthulhu Mythos campaign, because gaming groups who play Cthulhu the way it was meant to be played are going to lose. Since game groups aren't used to losing all the time, you need to decide where you want to set the difficulty level.
The first choice you'll need to make is whether to have a pulpy or gritty style to gun battles and melee combat. The pulpy damage system is the standard Savage Worlds damage, so your players will be able to take significant damage and have access to bennies for soaking wounds for what the designers call a "cinematic" feel. Gritty is a more lethal form of play, where every wound requires you to make a Vigor check to avoid a modified Incapacitation Table roll and bennies can't be used to soak damage. In this style, investigators better consider their options before leaping into combat.
The mental styles are Reality Blurs's way of adding insanity to the game. In many ways, this is the more important of the two considerations. Come across one of the truly monstrous horrors and a group of protagonists are going to die no matter what. It's dealing with mind-bending horror and insanity which makes Cthulhu gaming so different. The pulpy style lets the characters escape some Mythos encounters without long term mental side effects in the form of a Mental Disorder Table roll. In the gritty style, your players won't be able to spend bennies to fight off (or rationalize) mental trauma from their encounters with cosmic horrors. This makes fighting the monsters that much more horrible.
By mixing and matching these two decisions, you'll be able to create games where action is less dangerous, but insanity is a possibility around every corner. Or you can create a game where physical confrontation is dangerous, but insanity is less likely, to create a more sustainable campaign. Those are the middle options, because you can go to either extreme and play Cthulhu Mythos as either pulp tales or horror tales. You'll find other options which limit your benny count or you wild die.
Most of the other game elements from the old Call of Cthulhu game remain. Familiar investigator archetypes like antiquarian, clergyman, dilettante, and drifter remain. In fact, you'll have the full range of investigator options, including timeless standards like journalist, professor, and private investigator. Players will find they can tweak the archetypes a little more in Savage Worlds than they could in the Call of Cthulhu RPG.
You'll get a complete bestiary to pit against your investigators, from servitors like byakhee, tcho-tcho, and shoggoths, to the Great Old Ones like Yog-Sothoth, Hastur, and Cthulhu himself. The random tables let you roll up servitors or what type of tainted human the players encounter, just in case your players decide to go off the beaten path in their investigations and take the adventure somewhere you hadn't considered.
The rulebook contains random tables for hindrances, edges, minor gifts, and major gifts. You'll be able to figure out in a matter of seconds what kind of person the players are dealing with. Even if you have a well thought-out adventure in mind, I suggest you use these tables for inspiration. The servitor tables may be even more useful, since they let you add a horrible randomness to the creatures that often characterize the chimerical nature of Lovecraftian monsters.
Reality Blurs is a game design company that was founded in 2004 by Sean Preston. Top game lines in the Reality Blurs catalog include the "Oriental fantasy" game Iron Dynasty, the "dark steampunk" setting RunePunk, and the Gold ENnie-winning modern "horror espionage" game, Agents of Oblivion. Shaintar: Legends Unleashed is Sean Preston's fantasy setting said to be 20 years in the making, with plenty of traditional fantasy tropes packaged in a fresh and well-crafted framework.
Many of Reality Blurs's products are supplements for existing rule systems or open-gaming publications. These include the Mechagenesis robotic roleplay for True20 and Gearcraft supplement for True20 inventions and steampunk devices. The Old School Fantasy series offers fantasy adventures for Savage Worlds and Fantasy Craft rules.
If you prefer superhero or pulp tales, Reality Blurs offers several top-notch supplements. Powers & Perils: Orwell Industries is a complete write-up on a world-spanning business conglomerate to challenge your modern heroes, complete with a CEO motivated by visions of an impending apocalypse some years in the future. I've included this corporation in one of my own ongoing campaigns and the evil twist really got the players' blood up.
One of the most underrated games of the past 10 years is the Ravaged Earth pulp roleplaying setting, which uses the Savage Worlds system for game resolution. Ravaged Earth is meant to be a high-powered pulp game complete with a brilliant reason for why all these supermen and turban-wearing mystics have suddenly started wielding so much power. You haven't roleplayed until you've encountered the wondrous powers of mystic-powered hobos sworn to uphold Calhoun's Creed. I love the Ravaged Earth setting, which also fits in hard-boiled detectives, masked men, rocket rangers, and plucky reporters to this evocative pulp setting.
Reality Blurs brings a lot of inspiration and fresh ideas to its four continuing licenses: True20 Adventure Roleplaying, Chaosium Inc., FantasyCraft, and Savage Worlds. Cthulhu and Savage Worlds are a natural fit for each other.