Runequest Thursday #11: 'Mythos Society Guide to New England' Demonic Horse Runequestified!

Clint Staples

Since the Call of Cthulhu RPG and Runequest share the same basic system, it is not difficult to convert monsters for one to use in the other. Since I have recently written up a bunch of Mythos monsters for my Mythos Society Guide to New England, I thought it might be useful, and fun, to have them available to torment characters in Runequest, specifically my Brightwater Saga campaign

With that in mind, here is the first of these conversions , the Demonic Horse. I know, all you true fans of my column are saying "But this was the latest Mythos monster you wrote up. Why start with it? why not go chronologically?" To which I reply, "Do not allow yourselves to be bound by the strictures of linear chronology and euclidian geometry. Open you minds to the vast, terrifying cosmic vistas beyond the scope of such thinking. Contemplate the absolute meaninglessness of your exis . . . never mind."


Demonic Horse
A massive black horse of fiendish aspect, with glowing eyes, and carnivorous appetites. In Glorantha, demonic horses are referenced at least once that I am aware, as the steeds of Sir Ethilrist's Black Horse Company, a unit of mercenaries that has its own country, Black Horse County, a longstanding relationship with the Lunar Empire that does not preclude them from hiring out against it occasionally, and an immortal wizard-swordmaster who harrowed the Underworld to gain command of the beasts in question. I am not sure if these demonic horses are the ones in question, but they could be. And they would go a long way to helping explain why the Black Horse Troop is so kickass. Imagine a unit of sorcerer-knights on armored demonic horses in full charge. 

As a monster of Gloranthan folklore, the Demonic Horse could be something raised by a powerful enemy, a left over from the God Learners investigations into things best not known by men, the legendary 'haunt' of a particular local, or the product of a wizard's summons.

Some of the possible eldritch abilities may suit different roles better or worse.As a creepy encounter Breathe Fog, Swimming, Nightmare and Compel Rider go well together and could lead to a neat kidnap scenario or a 'demon horse sighting' sort of thing. In such a case, the GM may increase the INT of the demonic horse if desired, to reflect its level of cunning malevolence as required [INT 6 is the level of a very smart horse or dog, but not true sentience]. As the mount of the Black horse Company, a wizard, or even a PC, maybe 'Compel Rider' could be the trial that the rider must occasionally overcome to master the creature, getting easier with practice.

Regardless, the Demonic Horse is a powerful being, whether enemy, ally or somewhere in between.







Hit Points



R. Hind Leg







L. Hind Leg





















R. Front Leg







L. Front Leg





















Defense 10%












Damage Bonus +2d8

Armor 6 point of demonic hide.

Traits Night Sight

Skills Athletics 75%, Evade 30%, Listen 80%, Persistence 43%, Resilience 77%, Spot Hidden [Unaffected by fog or darkness] 60%, Stealth 50%, Survival 60%.



Bite SR 16 / 75% / damage 1D8+2d8 Damage Bonus

Kick SR 17 / 85% / damage 1D10 +2d8 Damage Bonus

Rear and Plunge SR 12 / 55% / damage 2D8 +2d8 Damage Bonus

Trample SR 10 / 50% / damage 2D6 +2d8 Damage Bonus


Eldritch Abilities [The GM should choose those that he likes]

Any actions occur on SR 15.

Compel Rider – Instead of attacking the demon horse can compel a single target to mount its back, at which point it will gallop off tirelessly for hours or days over land, sea and sea, effectively running its rider into exhaustion. The Demon Horse must succeed at a POW vs. POW check to compel. Each 1d6 hours, the rider may make  a POW x1 check to dismount wherever he happens to be.

Breathe Fog – Instead of an attack the demon horse can expel clouds of fog from its nostrils, creating an expanding foggy area. This begins as a 10 foot radius circle, but each round the demon horse Breathes fog in the same place, the cloud expands by another 10 feet in radius. Anyone in the fog, other than the demon horse, has -20% on Fighting, Spot Hidden,

Preternatural Swimming 10 – The demon horse can swim faster than crocodile.

Flight 16– The demon horse can fly by running across the sky, possibly treading the fog it breathes.

Nightmare – Once the demon horse has seen a person, it can invade her dreams, leeching her of vitality. Any time the victim is asleep, roll The demon horse’s POW or less on d100. On a success it comes to attack the sleeper with a POW. vs. CON check. If it succeeds, it inflicts a nightmare that drains the sleeper of 1d3 CON, which will also reduce their HP.] These CON return at a rate of 1 CON per night. If the victim is attack on successive nights, it may be ridden to death. As an alternative, you might choose to inflict one set of poison symptoms from p. 58 of ‘The Call of Cthulhu RPG’, 6 th Edition.

Underworld Travel – The demon horse can travel from our world to the Underworld at will, or perhaps only at dawn, dusk or midnight. A powerful master could compel it to carry a rider, but should beware if it has ‘Compel Rider’.

Preternatural Vigour - the demonic horse recovers from injury extremely quickly, perhaps restoring itself to health each dusk, or healing 1d10 HP per hour, at the Keeper's discretion.


Mastery of a Demonic Horse
In order to ride a Demonic Horse with any sort of security and control, a rider must first 'Master' it. This is similar to binding a spirit or elemental, requiring Spectral Combat between the prospective master and the horse. If the master has the means to initiate Spectral Combat [Spiritwalking, or spells or abilities such as Soul-Binder or Demon-Binding, etc] she may do so from a 'safe' distance, even from outside a Warding Circle. If not, she must mount the horse, which will initiate Spectral Combat as per Compel Rider. The Rider must reduce the Demonic Horse's POW to half or below its starting value, then may attempt to Master it by making a further successful attack and devoting 1 Permanent POW to the Bond. if the horse is mastered, it will surrender its true name, and remain under control so long as the master's Characteristic POW is higher than its own. If the master's POW is ever equal to that of the Horse, the demon will become fractious but not rebellious. If the master's Characteristic POW is lower than that of the demonic horse, the demon will rebel at any opportunity, usually by Compel Rider and then riding away wherever it wishes, possibly to the Underworld.