Saturday, 23 February 2019

The Astral Plane

This is my take on both the Astral and Ethereal planes of D&D. I always thought the two could be combined and made more interesting, so this is my current attempt at achieving this. This is based heavily off of interpretations of Astral Projecting in both D&D and in popular culture.

The Astral Plane is a ghostly locale where lots of spirits partially exist, and other races inhabit completely. The Astral Plane is in some ways extremely similar to ours, except separate structures that exist on the Astral Plane, and astral-projecting creatures are not visible on our plane unless the creatures specifically want to be seen. On the astral, what is going on in the Prime Material can be very faintly seen through mostly transparent figures. Interestingly, these figures are completely featureless when viewed from this plane, making its use for surveillance very limited.

When PCs travel to the Astral Plane, they separate their physical body from their astral body, and lose all control of their physical body until they return. PCs initially step into a small "safe zone", that is a clearly marked, 60ft radius sphere. This safe zone is effectively a pocket-plane, allowing the PC astral projecting to stay here without any risk of encounters with native astral entities. Only characters or groups moving beyond the safe zone are in any danger of encountering other creatures. A character cannot leave the safe-zone without being willing- an unwilling character treats it as a solid wall. Characters who are not native to the astral plane can pass through the walls of a safe-zone with no difficulty.

Creatures on the Astral Plane cannot target creatures on the Prime Material with attacks, and vice-versa, for the most part. A notable exception is Silver and Magical weaponry. These weapons can still target an Astral character. While this is a drawback, most extraplanar creatures (fiends, celestials etc), and all spirits also have some Astral presence. An astral-projecting PC can leap into the Astral plane and successfully hurt them with nonmagical weapons. Creatures on the Astral plane can divert any number of attacks to the PC instead of corporeal ones, and a GM may rule that the creature either has dice affected like humanoids do as above, or play by separate rules.*

Everything on the Astral Plane is practically weightless. Knockback effects now knock them back double the distance on a successful use of it. Furthermore, each PC has a jump speed equal to their fastest movement speed. The PCs' fastest movement speed is also the speed used for all movement on the Astral Plane. Two objects of roughly similar size impacting each other both fly back a distance equal to the total strength involved, x2.5ft, while a small object pushing off a large object flies back a distance equal to the total strength x5ft.

Additionally, there is near-zero drop-off for ranged weapons. This means any ranged weapon can shoot up to their maximum range with no penalty. However, this also means a stray shot will keep travelling at a strong speed until it either hits something or a really long time has passed.

In the Astral Plane, "up" and "down" are relative, and no character takes any kind of fall damage while on the plane. A character proficient in astral projection can change which is which on a whim, while a character who has not yet learned how it works thinks down is whatever they perceive it to be, but can figure it all out with training. It is not unheard of for fights in the astral plane to be three-dimensional slug fests that throw characters around great distances.

Every astral-projecting character has a silver cord that extends 1ft behind them. It actually extends further, but it's completely invisible and impervious to any damage beyond that distance. If the silver cord is cut, the character's astral body fades and the physical one goes into cardiac arrest. Both bodies die at the same time, in 1d3+1 rounds. Note that

A characters' Astral body has slightly different stats from their physical body. These stats that change are the following:
  • The characters' AC and Willpower** scores now equals their Wisdom score, without any modifiers. Manifesting or using a shield can raise this AC score though.
  • The characters' Reflex and Magic Resistance scores now equal their Intelligence score, without any other modifiers.
  • The characters' Fortitude defence is now equal to their Charisma score, without any other modifiers.
  • While astral projecting- the character counts as having proficiency with all weapons if they know one method that allows them to project. Otherwise, the character has weapon proficiencies as normal.
  • While astral projecting, the character can manifest any nonmagical normal or silver weapons they want, as a free action on their turn. Characters can also use the astral form of weapons they were holding when they projected if they want, too. Characters who cannot Astral Project on their own cannot do this initially, but can be taught how to do it by another character.
  • A character with knowledge on Astral Projection can manifest any nonmagical object as an action. This item is Astral-only, and will not come with them onto the Prime Material Plane.
  • All weapons on the Astral Plane do 1d6 damage on a hit. This damage die raises to 1d8 at 5th level, 1d10 at 11th level and 1d12 at 17th level. Weapons on the Astral Plane use the characters' Intelligence, Wisdom or Charisma as their attack stat. If the character has the ability to do Astral Projection, they may use their Spell Attack bonus instead of their physical Attack Bonus, even when making weapon attacks.
  • Note that using a weapon on the astral plane is purely a flavour thing or for one of the weapons' special properties (such as whip entangling), as they do the same amount of damage as an unarmed strike on that plane.
  • Other abilities that affect physical combat do not function in Astral Combat. For example, Regeneration has no effect because it's not the characters' physical body.
  • On the Astral Plane, no spells have any risk of burnout and any caster has the ability to Improvise a Spell, even if they couldn't normally.
  • While in astral form, the casters' body rests, and the casters' astral body suffers none of the ill effects that plague the casters' main body- their physical body sleeps while their astral body keeps watch, for example.

While this is all going on, the PCs' physical body is still intact on the Prime Material Plane. Any attack on the PCs' physical body while they are astral projecting automatically scores a critical hit. In my system, this means damage bypasses a large chunk of "Stamina" points and goes straight to HP. In your game of choice, you might decide that the character is automatically Incapacitated or Helpless or your equivalent.

If a PC enters the Astral Plane with a physical body, other things happen too:
  • The PC uses their actual defences instead of the ones listed above.
  • The PC cannot manifest astral items, and their weapons do normal damage.
  • The PC does not age, nor do they require food, water or sleep. Theoretically, a character can live for the rest of eternity on the Astral Plane with no ill effects. This is why the Githyanki value their slaves.

*In my home game, the current rule I am going with is humanoids play by the same rules PCs do, but other extraplanar entities do not unless they are also specifically astral projecting.
**Also, I have removed saving throws from my own game. Instead, things make attacks against different AC-like targets- AC, Fortitude, Reflex, Willpower and Magic Resistance. For example, a Wizard casting Fireball rolls to hit vs the Reflex defence of each target, instead of those creatures making saving throws. If you are playing a saving throw based game, you might wish to give characters bonuses/penalties to their saves equal to the relevant modifiers while they're here, or ignore this rule entirely.

Astral Based Spells
Astral Projection (Astral) [Ritual] (Range Self, Duration 12 hours, AoE the caster). The casters' astral body leaves their physical body for the duration of the spell, with astral copies of whatever items they have. Additionally, if the caster wishes, they can treat their Stamina maximum and current total as 4 x their level + their Spellcasting Ability Modifier while they are on the Astral Plane, if it is higher than their maximum Stamina total***. If the spell expires when the caster is still on the astral plane, they get reeled in to their body at a speed of 300ft/round, the spell ending when the caster returns to their body.
  • Level: 2

Group Astral Projection (Astral) [Ritual] (Range Self and 30ft, Duration 12 hours, AoE the caster and up to eight willing creatures). The group determined by this spell all simultaneously leave their physical bodies, with astral copies of whatever items they are carrying. Additionally, if the caster wishes, they can treat their Stamina maximum and current total as 4 x their level + their Spellcasting Ability Modifier while they are on the Astral Plane, if it is higher than their maximum Stamina total***. No other character in the group can do this.

If the spell expires when the caster or any others are still on the astral plane, they get reeled in to their body at a speed of 300ft/round, the spell ending when the caster returns to their body. This also immediately happens if the caster dies while on the astral plane.
  • Level: 7

Portal to the Astral (Astral) [Ritual] (Range 10ft, Duration Permanent, AoE a 10x10ft area). The caster creates a huge portal, which transfers anyone who steps through it to the astral plane. The portal lasts until the caster either dies or dismisses the spell. Astral natives who pass through this portal disintegrate, leaving only a charred skeleton on the other side.
  • Level: 5

Solidify (Astral) (Range Touch, Duration Permanent, AoE 1 incapacitated target). This is an evil spell employed by the Githyanki to capture slaves. An incapacitated target is afflicted by a curse, depending on their method of entering the astral plane:

If the character was astral projecting, then their physical body fades as their astral body becomes more solid. Their physical body has been teleported here. The character can escape by making it back to the Prime Material, somehow.

If the character was already physically here, then their link to their home plane is temporarily interrupted. As long as this curse persists, the character cannot leave this plane and is considered a native to the astral plane. This effect can be ended for 12 hours with a Remove Curse spell, and permanently if they escape back onto a Prime Material plane while under the effects of a Remove Curse spell.
  • Level: 4

Soul Separation (Evocation, Necromancy, Astral) (Range 60ft, Duration 1 minute or Concentration, AoE 1 target with a soul). Target creature is targeted by a spell attack vs Willpower. On a hit, the targets' astral form is forcibly separated from their body for the duration of the spell. The soul while separated follows the rules for astral projection, and the player controls their astral body for the duration of the spell.

However, during this time, the body animates as a Zombie of the appropriate type under the control of the caster. This zombie does not count towards the limit of undead a character can control. Once the spells' duration expires, the soul can be reunited with the body if they end a turn in the same space.
  • Level: 6

***In my game, HP and Stamina are split into two pools. Stamina is the damage a PC takes when they dodge, block and otherwise get out of the way of serious harm. This damage regenerates much faster than actual physical damage.


Githyanki of Eithlos
The Githyanki are some of the coolest creatures in D&D, a race of marauders that inhabit the Astral Plane. As inhabitants of the plane, they are in physical bodies and as such use all the rules for physical creatures on the astral plane where relevant.

Githyanki in the Eithlos campaign take full advantage of the lack of weight of most objects. They are usually on large mobile cities that they constantly have on the move, hunting other astral characters. When they have found their prey, they will speed towards them at a rate of 60ft a round and use Spearguns mounted on the cities to capture their targets. Enslaved targets will be robbed and put to work inside the mobile city. The largest mobile city, Mori'voodah, is a colossal airship with tens of thousands of Githyanki, and almost half that number of slaves aboard as well. The Githyanki there are ruled by a powerful Lich-Queen who rules with an iron fist, and destroys any Gith that becomes strong enough to challenge her supremacy.

I picture cities on the Astral Plane looking like the traction cities on Mortal Engines.

 These are the stats I use for Githyanki on the Astral Plane, considering all the rules above:
Armour: Variable- base AC is as Leather, but as they are physically inhabiting this plane, they can benefit from armour.
Hit Dice: Base 2 or by class
Hit Points: 10 or by class
Move: Standard
Damage: by weapons- see below
Manifest Objects: Any Githyanki can manifest simple objects as if they were projecting. More intelligent ones and ones with more class levels can manifest more.
Adapted to the Astral: Githyanki have lived their entire lives on the Astral plane, and will take full advantage of their knowledge in combat. They will leap, and attack from unexpected angles, usually granting advantage on their to hit rolls.

Githyanki Weapons:
Silver Swords: These have been with Githyanki since their first introduction. I rule them as longswords (1d8 damage in my game, or 1d10 if two-handing it). The sword can target the cord if they get a chance, which has an AC of 20. On a hit, a result of 8+ on the damage die severs the cord. If brought back to the prime material plane, these swords function as ordinary silver swords.

Githyanki Spear-gun: These spear-guns have a range of 300ft on the Astral Plane and inflict 2d6 damage on a hit. They then reel in the weightless character at a rate of 60ft a round. The character will be lifted off the ground by this attack and will likely be able to do very little about this. This is one of the main ways Githyanki capture their slaves.

Explosive Shields: These shields are rigged with explosive charges. When sundered, the shield explodes, inflicting 1d8 damage to the attacker and half that to the wielder. Both characters then get thrown back 2d6x5ft.

Githyanki SMGs: These rifles are huge diesel-punk looking devices that use their own ammunition type. Despite their size, they are light enough on this plane and recoil-compensated enough to function while being comfortably wielded on one hand. They're a higher calibre than most SMGs. In my own game, they use Assault Rifle statistics, with the additional bonus of +1 to hit from the large anti-aircraft style sights. I picture these weapons looking like the assault rifles in Fallout 4 


Assault Rifles: 2d8 damage, 300ft range, 30 round magazine. Any assault rifle can fire an increased burst, every extra bullet fired giving a +1 bonus to hit and damage. This stacks up to +5.

Other Encounters on the Astral Plane

Githyanki and their moving cities aren't the only things that characters can find on the Astral Plane. Despite being pretty deserted aside from the Prime structures and inhabitants, other inhabitants can be found if you venture beyond the safe zone:

Escaped Slaves
These characters are either unfortunate victims of the Githyanki's "Solidify" spell, or slaves obtained from another plane that were brought here. These characters use the rules for normal humanoids, but may be armed with stolen Githyanki weaponry.

Lost Souls
Occasionally, someone's astral body will be destroyed while astral projecting, but the astral body survives. These unfortunate victims now wander their own astral purgatory, without any way of getting home. If they find a group of astral-projecting travellers, they will attempt to attack one of the PCs, destroy their astral body and then grab the silver cord, following it to their body to possess it.
Armour: As Leather +1. All defences are 1d4+10 each.
Hit Dice: 1d8 dice
Hit Points: 4hp/die
Move: 1.5x Standard
Damage: 1 attack, 1d6+1 damage. At 5th level, this is raised to two attacks for 1d8+1 each.
Astral Projection: As an astral projection that is lacking a body, a Lost Soul can do anything that is listed above in combat on this plane. They may even know spells and be able to improvise them.

Astral Whales
Large space whales occasionally float around the astral plane, sometimes migrating in herds. They are mostly mindless, but very aggressive to something that crosses their path. It is strongly recommended that they are avoided, as they will give up chase as soon as something flees. They are occasionally hunted, because their blubber and ambergris are magically-infused and worth even more than a normal whales' produce, and are used in some spells.
Armour: Unarmoured
Hit Dice: 10+30 (50+30)
Hit Points: 80
Move: Fly 2x Standard
Damage: 2d8 Headbutt and 2d4 Tail Slap
Tail Slap: The whale can make one attack behind it and one in front of it in the same round. Both attacks knock a character back 30ft on a successful hit.
Astral Seafarer: Astral Whales are very aware of their surroundings. They will only be surprised on a 1 for initiative.
Astral Regeneration: Astral Whales are the only creatures known to regenerate while on the Astral Plane. They regain 3hp a round.
Song of the Astral Whale: Their whale-song can be heard for a long distance. Nobody can be surprised by an Astral Whale encounter unless they are deaf. This whale song changes during combat, each round having a 10% chance per round of attracting another Astral Whale that arrives in 1d6+2 rounds.
1/day: The Astral Whale can target its song on any hostile creatures within 90ft. The whale makes an attack vs Willpower (or save vs Spell). Targets affected are treated as if the whale put a suggestion spell on them, to cease fighting and leave in peace.
Album art is one of my favourite sources of inspiration


Dimensional Shamblers
Nightmarish creatures from the astral plane, Dimensional Shamblers capture creatures either on the astral plane or one of the primes, and takes them back to be devoured.
Armour: As leather +1
Hit Dice: 7+7
Hit Points: 42 (35+7)
Move: Slightly faster than a humanoid (35ft as opposed to 30ft in my game)
Damage: 2 claws 1d8
Silver or Magic Weapon to hit: Shamblers are immune to mundane weapons while on the Prime Material Plane.
Planar Jaunt: On a hit, the Shambler can attempt to grapple a target. If they succeed, the Shambler and the victim are both teleported to the Astral Plane, in the Shamblers' safe-zone. This is where the Shambler will attempt to finish off the character before devouring them. If relevant, the Shambler has a Str score of 19, for a +4 modifier.
2nd Person Vision: The shambler can only see creatures that can see it, while they are looking at it. A character who is blind or averts their eyes from the shambler are effectively invisible to it. Furthermore, the Shambler is incapable of grappling a target that isn't looking at it.



Independent Settlements
Not all settlements are under Githyanki rule. Some are settlements where slaves have risen up and overthrown their masters, and others are settlements simply built and made movable independently.

Due to the extreme weight reduction of everything on the Astral Plane and the amount of resources in Githyanki camps- coupled with the lack of need for other resources, entire cities of Astral inhabitants can be mounted on engines and driven around. Most astral inhabitants escape as soon as they can, but others stay here for a greater purpose- hatred for the Githyanki, desire to free the slaves or just liking immortality are all reasons for people to stay on the Astral Plane.


Junk City
Junk City is the largest known independent settlement in the Astral Plane, a titanic behemoth of steel made mostly of former Githyanki slaves and renegade Githyanki. Despite being hated by the Gith, the overwhelming size and force employable by Junk City's inhabitants plus the collective genius used to create its engines have also made it extremely fast for its size. Aboard Junk City are several mages and mystics (my campaign's Cleric equivalent), who can remove the curses from "indentured" characters and send them home through permanent portals on Junk City. Before they are let go, however, they are asked to join the fight against the tyrannical overlords on this plane.

Junk City is run by Keira Blackstrand, a human. She is centuries old, taken from her adventuring party by Githyanki raiders. She led a revolution and overthrew the reigning government on Junk City (formerly known as Melekkiyar), and ran a haven. Her ultimate goal is to abolish slavery on the astral plane. She is a 14th level Human Fighter (or Warlord/Tactician, if you have a class like that), who uses a Githyanki Silver Sword and a +3 Assault Rifle. In GLOG, she would have at least four templates, possibly more if you allow multiple classes.

Other notable figures on Junk City include:
  • Claudia Marsh, Human Wizard. Claudia intends to sabotage Junk City under orders from her Githyanki masters. She maintains regular contact with them, as they have a geas spell on her, and she uses sending (or a similar spell) regularly to keep them informed. If freed from the geas spell, she will immediately be able to tell them everything. Otherwise, she will answer any questions about her involvement with the Githyanki with "I cannot say".
  • Dareon Marsh, Claudia's brother and bard. Dareon suspects something is up with Claudia after they were rescued together, but doesn't know anything for sure and assumes it is more benign than it really is.
  • Ikarahan, Marid (Water Genie). Ikarahan (or "Ike" for short), is one of several marids that were used to power the steam engines of Junk City underneath the Githyanki masters. Most of the genies fled home to the plane of water when Keira's revolution succeeded, but Ike stayed behind in order to power the engines and free his kin on the other raiding settlements.

Sea of Tarrasques
Tarrasques are Godzilla in a D&D setting, nightmarish monstrosities that are overwhelmingly powerful. On the astral plane, sometimes entire herds of tarrasques can be found, peacefully slumbering. These tarrasques likely won't stir unless especially magically woken up, but there's exactly no reason why you should tell your players this. Roll stealth checks for them behind the screen, shake your head with a smile and have nothing happen.
Armour: As Full Plate armour
Hit Dice: 75
Hit Points: 375
Movement: About 2/3 Standard (Move 20ft compared to human 30ft)
Damage: 2 Claws 1d12 each, two horns 1d10 each, tail lash 2d12 and bite 5d10
Rush: Once per minute a Tarrasque can rush, essentially hasting itself for the round. During this time, the tarrasque simply moving through somethings' space forces an attack vs reflex/ dex save for 2d10 damage or half on a miss (successful saving throw)
Literally the scariest thing you have ever seen: This thing is huge, and terrifying. Creatures of 3HD or lower that see a Tarrasque flee immediately.
Regeneration: Regardless of what plane it is on, the Tarrasque regenerates 3hp a round automatically.
Almost Indestructible: The only way to kill a Tarrasque for good is to knock it unconscious, reduce it from 0hp to -30 while it regenerates, and then wish it was dead, via the spell.

Of course, this statblock will almost certainly prove to be worthless to you. There's not much chance that the PCs will be able to rouse these sleeping behemoths, even if they wanted to!


As always, opinions and feedback are gladly accepted!

Monday, 11 February 2019

Fiends in the Eithlos Campaign, v0.1

DISCLAIMER: I know that some people out there think RPGs really are about summoning demons and the like. This "spell" is a fictional spell, cast by fictional characters, in a fictional game where people basically do improv with dice. I am not a wizard, and I do not cast spells. Nor do I believe in magic, or condone summoning actual demons if I did think they existed. They're supposed to be creatures of ultimate evil- what kind of idiot would summon them?

Anyway, to the subject of this post:

I haven't really touched upon fiends in my own home OSR game, but with my current group getting closer and closer to level 5 as of me writing this, I think it's best to be prepared for when that happens- after all, even if none of the players think fiends are worth the risk, I might include non-player character villains who use fiends against my group of heroes! 

I've based this version of the spell heavily off of the Summon spell from LotFP, but changed the random entity determination out for a list of fiends that exist in my home game, and made a few other alterations as well. 

If your campaign uses fiends, but not the types seen in D&D books, then I've left a few notes in this post to help you add your own fiends to the table. If you don't use D&D fiends and don't have any of your own, there's only a few things here that will be of use to you.

In my home game, I make this a level X spell, like I do with the Summon spell. This simply means the spell can use any spell slot size, and the bigger the spell slot expended, the more powerful the spell is.


Summon Fiend (Conjuration) [Ritual] (Range 10ft, Duration Special, AoE 1 or more spaces in range).
This spell opens a rift between our world and that of one of the fiendish planes, and forces an inhabitant from beyond our world to do the casters' bidding. The creature itself could be any type of fiend. Both what it is and whether it will do as told is very unpredictable.

There are several steps for the Summon Fiend spell:
  1. The caster chooses the power of the entity he or she is trying to summon.
  2. The caster makes a saving throw.
  3. The GM determines the entity summoned.
  4. The caster attempts to dominate the creature.

STEP ONE - NAME THE ENTITY
The character call the name of the Fiend they are attempting to summon. If you don't know any fiend names, you cannot cast this spell. It is STRONGLY recommended that you summon a creature with less than double your level.

The character can also choose to summon multiple demons with the same spell. However, doing so is extremely risky, as shown in the rules for the Domination roll.

The caster also chooses how much money they will spend on the ritual and in valuable offerings to sacrifice, or live creatures sacrificed in the summoning. Every 500sp spent making a thaumaturgic circle or 2HD offerings for the creature gives a +1 bonus for the Domination check.

STEP TWO - MAKE A SAVING THROW
The character rolls 1d20, and compares the result to the required total on the table. As long as they rolled at least the relevant result, the save is considered to be passed:
Levels
Save
1-5
14+
6-10
12+
11-15
8+
16-18
6+
19-20
4+
Failing this save has dire consequences- you are no longer in control of the power of the fiend summoned by this spell.

STEP THREE - DETERMINE ENTITY
The GM rolls one die, determined by the tier the character is summoning:
Least Fiend: 1d4
Lesser Fiend: 1d6+3
Greater Fiend: 1d6+8
True Fiend: 1d8+12
Failed your Saving Throw: 1d20.
Note: If a result "the type called for" comes up and the class of Fiend is different to the one the player aimed for, the GM chooses the Fiend type.

Die roll
Result
1
Least Fiend, but different to the one intended to be summoned.
2-4
Least Fiend, the type called for.
5-6
Lesser Fiend, but different to the one intended to be summoned.
7-9
Lesser Fiend, the type called for.
10-11
Greater Fiend, but different to the one intended to be summoned.
12-14
Greater Fiend, the type called for.
15-17
True Fiend, but different to the one intended to be summoned.
18-20
True Fiend, the type called for.

List of Fiends in the Eithlos Campaign:

Fiend
Type
Tier
HD
HP
Total Domination Roll
Dretch
Demon
Least
2
10
1d20+2
Lemure
Devil
Least
2
10
1d20+2
Imp
Devil
Least
2+2
12
1d20+2
Manes
DemonLeast151d20+1
Quasit
Demon
Least
3
15
1d20+3
Spinagon
Devil
Least
3+3
18
1d20+3
Rutterkin
Demon
Least
4
20
1d20+4
Armanite
Demon
Lesser
5
25
1d20+5
Maurezhi
Demon
Lesser
5
25
1d20+5
Osyluth
DevilLesser5251d20+5
Barbazu
Devil
Lesser
6+6
36
1d20+7
Bar-Lgura
Demon
Lesser
6+6
36
1d20+7
Erinyes
Devil
Lesser
6+6
36
1d20+7
Kocrachon
Devil
Lesser
6+6
36
1d20+7
Yochlol
Demon
Lesser
6+6
36
1d20+7
Hamatula
Devil
Lesser
7
35
1d20+7
Uridezu
Demon
Lesser
7
35
1d20+7
Bulezau
Demon
Lesser
7+3
38
1d20+7
Nabassu
Demon
Greater
7+10
59
1d20+10
Vrock
Demon
True
8
72
1d20+10
Chasme
Demon
Greater
8+2
58
1d20+9
Babau
Demon
Greater
8+14
70
1d20+11
Amnizu
Devil
Greater
9
63
1d20+10
Malfera
Neither
n/a
9
63
1d20+10
Hezrou
Demon
True
9
81
1d20+11
Cornugon
Devil
True
10
90
1d20+12
Glabrezu
Demon
True
10
90
1d20+12
Alkilith
Demon
True
11
99
1d20+13
Gelugon
Devil
True
11
99
1d20+13
Nalfeshnee
Demon
True
11
99
1d20+13
Molydeus
Demon
Guardian
12
74
1d20+13
Marilith
Demon
True
12
108
1d20+14
Balor
Demon
True
13
117
1d20+15
Pit Fiend
Devil
True
13
117
1d20+15
Wastrilith
Demon
Greater
15
105
1d20+14
Goristro
Demon
Greater
20
140
1d20+10 (Low Intelligence)

Adding your own Fiends to the list:
The bonuses for the domination rolls consider a few things:
  1. The hit dice of the fiend is important. They gain a default bonus to this roll equal to their HD.
  2. Greater or Guardian fiends get a +1 bonus to the roll.
  3. True Fiends get a +2 bonus.
  4. Conjuring more than one fiend still only has one domination check, but each additional fiend beyond the first gives a bonus to the fiends' side of the check- +1 for every additional least/lesser fiend, +2 for every additional greater fiend and +3 for every extra True fiend.
  5. Particularly stupid fiends (like the Goristro), have their bonus halved, rounded down.

As for how I calculated HP, I determine the hit die size (and thus, the average HP) using the following method:
  • Least and Lesser fiends use d8s, 5hp/die
  • Greater and Guardian fiends use d10s, 7hp/die
  • True fiends use d12s, 9hp/die

STEP FOUR - WHO IS STRONGER?:
The caster rolls 1d20 + their level + their appropriate prep modifiers, and compares this to the creatures' roll, the rules of which were just mentioned above.

If you expend a spell slot higher than 1st level for this spell, you gain a bonus to your domination roll. Consult the table below for specifics:
Slot Level
Bonus
Ritual/ 1st level
+0
2nd-3rd level
+1
4th-5th level
+2
6th-7th level
+3
8th level
+4
9th level
+5

If the caster wins:
  • They roll 1d10 for every point their score exceeds the creatures'. The creature serves the caster for this time as long as the caster spends every action maintaining concentration. If concentration is broken, another domination roll must be made on the casters' next turn or the creature is loose. If the duration expires, the creature returns to its own plane.
  • If the caster wins by 5 + creatures' Hit Dice + the amount of powers it has, the caster immediately casts the Geas spell. The creature serves the caster until the service is filled, without the need for concentration. It returns home when its service is fulfilled.
  • If the caster wins by 19 or more, the creature is permanently on our plane, and under complete control of the caster.
  • Furthermore, if the caster wins, the Fiend is unable to cross any thaumaturgic lines or circles that the character has drawn.

If the creature wins:
  • It will lash out, and try to kill all living creatures while in this reality- although it will concentrate solely on the caster until their demise. It lasts for 1d10 rounds for every point its score exceeded the casters', to a maximum number of rounds equal to its Hit Dice.
  • If the creature wins by 5 + casters' Hit Dice + sacrifice and ritual bonuses, the caster is at the complete mercy of the creature. Roll on the dominating creature table below.
  • If the creature wins by 19 or more, roll 1d20. On a 1-19 it is empowered by its own dimension. It multiplies its HD total by 1d4+1 and then goes on a rampage. On a 20, the barrier between realities is damaged, and all manner of rifts will open into our world. The end times have begun prematurely. Dozens of fiends, elementals and other extradimensional entities will be stranded here, and there will be chaos all over the world.

If the result is a tie:
  • Roll again, but with 1d12. The caster doesn't get to add the bonuses for the ritual or sacrifice. If a tie is again indicated, the creature wins the tie by 1.

Dominating Creature table:

1d6
Result
1
The fiend(s) returns to its own reality, with the caster as a pet. The physical body is still intact and preserved, but won't wake up unless the soul is rescued. The caster finds themselves in a cage not unlike a birdcage, with thousands of other condemned souls in their own cages across the creatures' lair.
2-3
The fiend hops into the casters' body. The creature has complete control over the casters' body until an exorcism is performed.
4
The fiends holds the rift open, and 1d10 more lesser fiends come. Each one is weaker than the main Fiend, and subservient to it.
5
The fiend's escape went wrong. Both it and the magic-user merge. They are effectively a lycanthrope. The character is in control, but the creature can make Willpower attacks at any time to take over. The mind in control matches the body of the being. If one dies, so does the other. If the Fiend is freed, it will immediately attempt to seize the caster's soul as retribution.
6
The caster and a random related creature swap bodies once the creature enters our reality. Both characters lose 1d20 sanity from the change. The creature explodes, and showers everyone with goop.


As always, feedback, opinions and whatever else you might want to say is appreciated!