Yog-Sothoth, Opener Of The Way
Sandy Petersen's Cthulhu Mythos - Pathfinder

Yog-Sothogh, Opener Of The Way

CR 29; XP 6,553,600
CN Outer God of gates, time, and space
Primary Source H. P. Lovecraft, “The Dunwich Horror”


Domains Darkness, Chaos, Knowledge, Travel, Void
Subdomains Dark Tapestry, Exploration, Memory, Night, Stars, Thought
Favored Weapon dagger
Symbol black spiral
Temple hilltops, observatories, orreries, standing stones, stone towers
Worshipers astronomers and stargazers, deranged spellcasters, fringe scientists, philosophers
Servitors outer mutants, outer abominations, outer spawn

Influence (DC 34)

Area 1-mile radius; Nucleus 15-ft. square
AC 47; Saves +30; hp 720
Effects control magic, limited mobility, desiccating touch, limitless, multidimensional, traverse


Combat Yog-Sothoth’s influence may be ended via damage inflicted to its nucleus.

Dimensional Block If a spell effect that blocks dimensional travel, such as dimensional anchor, dimensional lock, or forbiddance is cast at Yog-Sothoth’s nucleus (if the spell targets a creature) or wholly within his area of influence (if the spell affects an area), and the spellcaster manages to maintain control of the spell (see Control Magic, below), there is a percentage chance equal to the caster’s level that Yog-Sothoth’s influence stage is reduced by 1. If this reduces his influence to 0, then Yog-Sothoth’s departs for another dimension.

Portal Destruction Yog-Sothoth’s manifestation depends on a physical or magical portal. If this portal is destroyed, Yog-Sothoth’s influence immediately ends. The exact nature and defenses of such a portal are left to the GM to determine, but in most cases destroying a portal should require the use of a special artifact, a dangerous ritual, or a certain set of conditions that require coordinated teamwork and several rounds of work.

Influence Effects

Control Magic When a spellcaster casts any spell within Yog-Sothoth’s influence, Yog-Sothoth can opt to control the magic. In this case, the spellcaster must make a successful caster level check against the influence’s DC. If the check fails, Yog-Sothoth can immediately transform the spell into any other spell of equal spell level from the spellcaster’s spell list, and Yog-Sothoth then makes all the decisions involving targeting the spell and any other choices required to resolve the spell’s effects. If he so wishes, Yog-Sothoth can simply cancel the spell entirely. Yog-Sothoth can attempt to control spell-like abilities in this way as well, but if he’s successful, he cannot transform the spell-like ability into a different spell-like ability—he controls the spell-like ability’s targeting and choices, and can opt to cancel it entirely if he wishes.

Desiccating Touch At the start of his turn as a swift action, Yog-Sothoth sends several spheres, roots, and filaments of his body through a target within 15 feet, inflicting 3d100 points of damage and 1d6 points of Constitution drain. This hit point damage is never reduced by damage reduction, hardness, or resistance, but a successful Fortitude save halves the damage and negates the Constitution drain.

Limited Mobility Yog-Sothoth’s nucleus is mobile within the area of its influence, and can travel at a fly speed of 200 feet. He cannot exit his area of influence.

Limitless At the start of each round, Yog-Sothoth can instantly replace damaged or destroyed portions of his nucleus, healing 25 points of damage.

Multidimensional All weapon attacks directed at Yog-Sothoth’s nucleus have a 50% chance of passing through a portion of Yog-Sothoth that exists beyond the third dimension. Such attacks deal no damage to him. If the attack was made with a manufactured weapon and the attack’s damage is negated in this way, the wielder of the weapon must make a successful Reflex save with a DC equal to the influence DC or the weapon is whisked away to some other dimension or time. A weapon lost in this way may be retrieved via a miracle or wish.

Traverse All creatures chosen by Yog-Sothoth within his influence gain a fly speed equal to twice their land speed (perfect mobility), as well as the ability to cast teleport as a spell-like ability as a swift action at will.

Yog-Sothoth is frequently said to be conterminous with all space and time. While this is undoubtedly true on some level, Yog-Sothoth cannot physically intervene in the waking world most of the time, but must be summoned to do so. When a magical gate is opened for his passage, Yog-Sothoth can intrude into the mortal realms temporarily, to seek sacrifice or to advance his cause. However, only a fragment of Yog-Sothoth can normally penetrate our realm. For his whole reality to enter the waking world, a gate of colossal size must be prepared. Fortunately for life and sanity, this is difficult to accomplish, and requires much preparation. Nonetheless, if the procedure is successful, once Yog-Sothoth enters fully, he brings about the end of the world.

Yog-Sothoth is an utterly alien being, sometimes described as a congeries of spheres, but the reality is far more terrifying. These “spheres” are bladders or spawning sacs, and the whole is loosely knitted together with rootlets to form a semi-coherent body. The individual sacs can change their three-dimensional relationship with one another, and even operate when separated at a distance, but typically hang together.

Sometimes Yog-Sothoth can separate a chunk of himself to act semi-independently and even travel about in the mortal realm, but this typically can only last for the length of time his gate passageway is opened (rarely more than a few hours).

Yog-Sothoth is able to fly, travel between dimensions, and grant such travel to his minions and those who seek him out.

Yog-Sothoth Manifested

When Yog-Sothoth is called forth to take on physical form, he must literally squeeze through the portal that is opened for his presence. Except in the rare case of a full appearance, the gate is never large enough to permit the protrusion of more than a small part of Yog-Sothoth. This small portion is huge compared to a humanoid and is capable of both magical and physical threats. Yog-Sothoth is often summoned forth to intermix genetically with humankind, giving rise to outer mutants, abominations, or spawn, or else to teach dark secrets to his minions. When he does so, he usually requires sacrifices. When seen in his aspect as the unreality between dimensions, he is known as Umr at-Tawil, and is covered by what appears to be a cloth. This is probably his least malign manifestation.

Yog-Sothoth in Combat

That portion of Yog-Sothoth which reaches through a gate can attack by detaching globules from his body, which fly independently through the air and strike at his foes, or he can reach out with the tangled rootlets that form his internal structure, which become like antennae to strike. The touch of Yog-Sothoth brings about desiccation and death to the part of the body struck, but he does not merely cause this damage by contact. His orbs and rootlets are otherworldly and multidimensional and literally pass through foes, causing damage internally as they do so.

Yog-Sothoth himself is not fully on any one three-dimensional plane of existence, and physical weapons have only a limited effect on him. Of course, even if a portion of him is destroyed while extruded through the gate, he can push more into the area. Yog-Sothoth’s full size is at least hundreds of miles or kilometers across, so destroying a few cubic feet or meters of his local presence causes him little concern.

Yog-Sothoth has complete control of all the magical flux within his environs. Any spells cast might be repurposed, modified, and redirected by Yog-Sothoth, except for a few ceremonies powered by ancient artifacts of the Elder Gods or Great Old Ones themselves. A caster might maintain a spell through intense force of will, but this is rare. Yog-Sothoth’s minions are well aware of this ability and typically cast spells recklessly in his presence, expecting Yog-Sothoth to turn all such spells into useful aids.


Yog-Sothoth is one of the most powerful beings in the Cthulhu Mythos. (Indeed, Lovecraft never used the phrase “Cthulhu Mythos”, inventing the term “Yog-Sothothery” to refer to his created mythology.)

Yog-Sothoth is one tough cookie. Not only are physical attacks almost useless against him, as he can easily replace a damaged body part with more mass from his interdimensional self, but he twists and distorts most magic spells. For example, should a bold wizard hurl a meteor swarm at Yog-Sothoth, the Outer God can redirect it at the wizard’s allies or change it into any other 9th-level spell from the spellcaster’s spell list. For example, Yog-Sothoth might turn it into a dominate monster and target the wizard in an attempt to force him into some other course of action.

The result is that the best way to deal with Yog-Sothoth is in fact not to battle him directly, except for the minimum needed to stay live. Instead, try to destroy the arcane passageway giving him access to our realm. Once it closes, he must immediately depart.

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