So, you've seen the half-fiend template in the Monster Manual, but you want to add a bit more variety to your half-fiends. Take a look at this series of web enhancements that suggest how you can do that. You'll find basic rules for making your half-fiend more like the base fiend that you choose to use, plus you can start implementing these rules right away by using the statistics for several half-fiends that are within these PDFs.
The Monster Manual says that fiends can mate with almost anything and that such a union produces a half-fiend. However, half-fiends in the Monster Manual are all the same no matter what fiend did the mating. That doesn't seem fair, since dragons can also mate with just about anything and the half-dragon template gives different abilities and immunities based on the dragon involved -- and so a half-succubus should be quite different from a half-marilith or a half-goristro or a half-pit fiend. To rectify this miscarriage of justice and give fiends more input into the nature of their progeny (as if they needed it), let's consider how to modify the half-fiend template to make your half-fiends unique and more interesting.
As we work through the half-fiend template, the original Monster Manual text will appear in shaded boxes, and our discussion of modifications will be presented in regular format.
Creating a Half-Fiend
Good so far. At this point in the process, you should have chosen a specific fiend on which to modify this template, and the base creature to which it will be applied. We'll call the chosen devil or demon the model fiend. The model fiend must be corporeal. You should not choose a demon lord or devil prince, but an aspect of one is fair game. Rulers of the Lower Planes have better things to do than go around mating with lesser creatures.
A very small number of fiends are Huge, and their hugeness gets passed to offspring. If the model fiend is Huge size or bigger, and the base creature is size Large or smaller, then increase the base creature's size by one category. The relevant changes to the base creature's statistics can be found on page 291 of the Monster Manual. If the base creature increases in size, increase the CR of the final creature by 1.
Not all fiends have bat wings, though. What if the model fiend is a bebilith? Wings don't make sense, so add wings only if the model fiend has them. In compensation, if the model fiend has a swim, climb, or burrow speed, give the base creature the same mode of movement with speed equal to half its base speed (or the normal speed of the base creature in that movement mode, whichever is faster).
Demons and devils have different amounts of natural armor. Divide the model fiend's natural armor bonus by 4 (round down), and add that to the base creature as an improvement to its own natural armor. You should always add a minimum of +1 natural armor improvement, even if you find a model fiend with less than a +4 natural armor bonus. This creates a bonus in the +1 to +5 range.
Not all fiends have bites, and some might not even have claws. See the balor, the succubus, and the chain devil as examples of creatures that lack one or both of these attack modes. Give the half-fiend whatever natural attacks the model fiend has or that the base creature has. If the model fiend has only claws, but the base creature has claws and a bite, the final creature ends up with claws and a bite. If the model fiend has claws, and the base creature has slams and tentacles, then the final creature has claws and slams (the claws appearing at the ends of tentacles).
From the above step, your half-fiend might not have a bite attack, or might not have claw attacks. Use the base creature's damage for the attacks, or the value in the table on page 148 of the Monster Manual, whichever is greater. For damage other than claws and a bite, such as a slam, use the base creature's damage.
Given that no demon or devil has the smite ability (at least, not as far as I could find), we'll leave it in. The spell-like abilities are where you can customize to your heart's content, and where it is most appropriate to customize. Not all demons or devils have the abilities listed in the table on page 148 of the Monster Manual. In fact, most don't have them (especially the higher level ones). So, to make your half-fiend more personal, you can replace any ability at any level with an equivalent one that the model fiend has. In doing so, you should be thinking not of comparative spell level, but of comparative combat effectiveness.
For example, succubi have charm monster as a spell-like ability. That could be very useful in combat, much more so than desecrate and probably more so than poison or maybe contagion, but not nearly as good as blasphemy. So it could replace poison or contagion, depending on your final evaluation.
Don't go crazy swapping these abilities, though. You don't need to duplicate all the model fiend's spell-like abilities. And definitely keep them to 1/day or 3/day; no half-fiends need at-will spell-like abilities.
These abilities probably go well with all half-fiends, since all demons and devils have darkvision and are immune to poison and have energy resistance or immunity. The one place you might customize here is the creature's damage reduction type (the numbers above are good). Demons and devils don't have DR X/magic; they have DR X/good and/or either cold iron or silver. And besides, most everyone has magic weapons, so make things a little more interesting. So, change the damage reduction to match the model fiend, though you should only choose one kind if the model fiend has two. The creature's natural weapons would be treated as good if it has DR X/good, but not as a metal type if that is what you go with.
So, for example, a balor has DR 15/cold iron and good, so your half-fiend modeled on a balor could have DR X/good or X/cold iron, but not both.
Remember that HD for determining spell resistance means racial HD, not those gained with class levels.
These adjustments may not fit the model fiend very well. Let's rearrange them in a more fluid way. The total modifier for the template is +16 ability points. To see how the model fiend's stats are weighted, you can just look at them, or you can do a more complex math calculation. Subtract 10 from all even ability scores, and 11 from odd ones, to get the model fiend's ability modifiers. Then, assign your +16 points in a proportional manner to the modifiers of the model fiend, though you should not give any ability more than a +8 modifier. Because the half-fiend template doesn't modify Wisdom, I don't suggest that you rearrange your modifiers to affect the base creature's Wisdom score.
For example, a succubus has Str +2, Dex +2, Con +2, Int +6, Wis +4, and Cha +16. A good fit here might be Str +2, Dex +2, Int +4, and Cha +8. For the glabrezu, which has Str +20, Dex +0, Con +20, Int +6, Wis +6, and Cha +10, you might choose Str +6, Con +6, Int +2, and Cha +2.
Treat skills from the model fiend's skill list as class skills too.
The changes may have made the new creature more difficult to defeat than a base half-fiend. That is really a judgment call. An additional +1 natural armor won't make a difference, but +3 natural armor and a Strength +6 and Constitution +6 might. If you think the new creature is more difficult to defeat than it would be with the base half-fiend template, apply the Challenge Rating increases above and then add +1. Remember to add 1 if the creature changed size; a larger size always makes something harder to defeat.
These are unchanged.
As for the appearance of a customized half-fiend, you are free to use your imagination. You always were, but the template presents things so generically that all half-fiends tend to look like the base creature with wings, red eyes, and fangs and claws. However, you have a lot of room in which to play. A half-glabrezu creature could have one pincer instead of a claw, a half-succubus would be exceedingly lovely for whatever species the base creature is (even trolls and hags), a half-marilith might have a tail and extra arms that do not function, and a half-balor might have a glow to its skin that reminds one of the fiery aura of the toughest of demons.
Now that you can see the general methodology, let's apply it to some sample demons and see what happens. Each creature entry lists the changes for the customized half-fiend template, so you can apply the template easily to any other creature that qualifies.
Marilith/Hill Giant Combination
The combination of marilith and hill giant produces a brutish simian-looking giant about 11 feet tall with thick brown hide and four overlong arms that hang from its stooped shoulders. Its skin is smoother than usual for hill giants, and its long black hair looks less unkempt than typical. Its second set of arms move, but the creature cannot control them well enough to use them as weapons or to wield weapons. An 8-foot tail that resembles a thick snake extends behind the creature and twitches as it attacks.
Customized Half-Fiend Template
Half-Fiend (Marilith) Hill GiantCR 11
Smite Good (Su) Once per day this creature can make a normal attack and deal +12 damage against a good foe.
Rock Catching (Ex) A half-fiend giant of at least Large size can catch Small, Medium, or Large rocks (or projectiles of similar shape). Once per round, a half-fiend giant that would normally be hit by a rock can make a Reflex save to catch it as a free action. The DC is 15 for a Small rock, 20 for a Medium one, and 25 for a Large one. (If the projectile provides a magical bonus on attack rolls, the DC increases by that amount.) The half-fiend giant must be ready for and aware of the attack in order to make a rock catching attempt.
Goristros are huge bull-headed demons that flatten just about everything into which they run. Combined with a centaur, one gets a centaur that is covered in brownish fur over its whole body. The creature has a set of wicked-looking bull-like horns that it cannot use to attack. Its arms are a little longer than usual for a centaur, and its face is a tad elongated in a way that suggests a bull without really looking bull-like.
Customized Half-Fiend Template
*Note: You could also choose to make Con +8 and Cha +0, but I chose to increase Charisma.
Half-Fiend (Goristro) CentaurCR 6
Robert Wiese entered the gaming hobby through the Boy Scouts and progressed from green recruit to head of the most powerful gaming fan organization in the world. He served as head of the RPGA Network for almost seven years, overseeing the creation of the Living Greyhawk and Living Force campaigns, among other achievements. Eventually, he returned to private life in Reno, Nevada, where he spends as much time as possible with his wife, new son Owen, and many pets.
He is still involved in writing, organizing conventions, and playing, and he models proteins for the Biochemistry Department of the University of Nevada, Reno.
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