These rules are specific and detailed, but they are intended to be abstracted and estimated in play. Don’t feel obligated to track each creature’s Nexus Rank unless you want to for some reason, such as a campaign that centers on the war between two factions over a Nexus.

Additionally, it’s probably not best to overuse powerful Nexuses. these are meant to help build a theme for an adventure, not to be omnipresent and pedestrian. Tracking Signature and Countersignature conflicts and interactions is all right once in a while, but it can quickly lead to drudgery.

Nexuses are designed to bring magic and wonder to the campaign, not to overwhelm the players with complexity. Keep your Nexuses as rare, simple, and magical as possible, and they will make the setting shine.

— R. Scott Kennan

Nexus Rules

Thraxis is awash in Places of Power. In these places, certain magics and effects are enhanced, while others are hindered. These Places of Power are called Nexuses.

Nexuses have a powerful energy all their own, from the combustive realm of Mount Vosk where metals that can be forged nowhere else bend to the will of the azers and the hardy Garhai who work them, to the sacred halls of the Shrines of Nepri where prophets see distant Ages that even they cannot fathom. 

Technically, there are two forms of Nexuses, Local and Personal. Local Nexuses affect the magic of an area, while Personal Nexuses affect an entity alone, but contribute to the formation of a Local Nexus. When a Nexus is referred to without a qualifier such as "Local" or "Personal", the text is referring to a Local Nexus.

Nexus Types

Nexuses Types are named for the energy that the promote- called their Signature. The energy that that a Nexus hinders is called it's Countersignature. Nexuses are never named for their Countersignature. Signature and Countersignature are each drawn from the list of Nexus types, below.  

Nexuses come in 31 known types, that scholars place into several categories. These categories are not intrinsic to the Nexuses, and several Nexus types have been the subject of fierce debate as to their placement. 

Ethical and Moral Nexuses

  • Anarchic - Chaos and wild magic. 
  • Axiomatic - Law and restriction. 
  • Benevolent - Good and purity. 
  • Profane - Evil and cruelty. 

Expressive Nexuses

  • Alien - Cosmic strangeness and horror.
  • Creative - Conjuration and crafting. 
  • Deranged - Insanity. 
  • Divinatory - Divination.
  • Deceptive - Illusions.
  • Enchanted - Enchantments.
  • Fierce - Damaging Effects. 
  • Primal - Primitive forces. 
  • Shielded - Abjuration.
  • Psionic - Psionics. 

Elemental Nexuses

  • Auran - Air and wind effects. 
  • Aquan - Water and liquid effects.
  • Charged - Positive energy and Lightning.  
  • Cacophonous - Sound and Thunder.
  • Caustic - Acid.
  • Frigid - Cold.
  • Ignan - Fire
  • Solar - Radiance and light. 
  • Terran - Earth and mineral effects. 

Monstrous Nexuses

  • Aberrant - Aberrations.
  • Celestial - Celestials.
  • Draconic - Dragons.
  • Fiendish - Fiends. 
  • Insectoid - Insects and arachnids.
  • Fey - Fey.
  • Vegetative - Plants.
  • Necrotic -Undead and dark necromancy. 

LOCAL NEXUSES

A Local Nexus is a place where certain magics and mundane events are more powerful than usual, and certain other magics and mundane events are weaker than usual. The effects that are empowered in a Nexus are called Signature Effects, while the effects that are weakened are called Countersignature Effects. Signatures and Countersignatures are broken down into broad categories such as Axiomatic (lawful effects), Ignan (fire-based effects), or Necrotic (effects relating to death and necromancy.)

Signatures and Countersignatures work in pairs.

Nexus Rank

Signature and Countersignature strength ranges from Rank 0 to Rank 5. Rank 0 means that there is no particular Signature or Countersignature of that type, and magic and other effects are handled normally.

As a Signature goes up, its Countersignature goes up by an identical amount, except in extreme circumstances, such as the will of a god or an artifact. So for example, if an area had an Ignan Signature of 5, its Frigid Countersignature would also be 5. A Nexus consists of at least one Signature, and at least one Countersignature. Signature always comes first when they are listed.

NEXUS EXPRESSIONS

A Nexus's Signatures and countersignatures are written in the following format:

Signature1 / Countersignature1 [Rank] and Signature2 / Countersignature2 [Rank]

This is called a "Nexus Expression".

As you can see, you may have more than one Signature/Countersignature pair in an area, as long as all the pairs match up and exactly cancel each other out (again barring the will of a godlike entity or an artifact). So for example, you might have an area that was:

Benevolent / Necromantic: 5 and Axiomatic / Deranged: 3

If an area doesn't have a specific Nexus Expression, magic works normally. It may be necessary to note a Rank 0 Nexus if an event changes the Signature or Countersignature of an area, however.

UNBALANCED NEXUSES

It's possible for a Nexus to be unbalanced, if an opposing Signature or Countersignature comes from a different, balanced pair. For example, if a Nexus was both Ignan/Necrotic: 3 and it overlapped with an area that was Necrotic/Aquan 1. The Necrotic Signature would reduce the Necrotic Countersignature by its value in the overlapping area. The unopposed terms would be unaffected.

In the case that a Local Nexus is Unbalanced, the notation is as follows:

Benevolent: 1 / Necromantic: 5

The above area has a very strong Necromantic Countersignature, but only a weakly Benevolent Signature.

Nexus Spellcasting

Spells that you cast in a Nexus are affected by its Rank.

• Add the area's Nexus Rank to the effective level of the spell slot used to cast a Signature spell. This means that by spending a lower level slot, you can cast a spell that requires a higher level slot (as long as you know it), or that you can receive the benefits of casting a spell with a higher slot without actually expending a slot of that level. The maximum level for a spell slot is 9th. 

• Subtract the area's Nexus Rank from the effective level of the spell slot that you use to cast a Countersignature spell. This means that you must cast a lower level spell with a higher level slot to make it work at all, and that certain spell levels will be impossible to cast, as they will require a slot that doesn't exist. 

Nexus Formation and Effects

The strength of a Nexus has an effect on the environment and entities that live in it, per the Nexus Effects Table, below. 

Nexus Effects Table

Signature or Countersignature Strength Type Effects Time to Change Radius per Individual Transformation DC
0 (Not a Nexus) Everything works normally. 2 Months - 0
1 Vested There may be some strange effects in the area, Signature effects work slightly better, and Countersignature effects are slightly hindered. 4 Months 400 Feet 5
2 Pervaded Beings in the area are notably infused with the traits of the Nexus, mundane effects are more likely to be affected, and any sapient being can at least recognize the Signature of the area, with enough time. Effects are more seriously influenced. 6 Months 800 Feet 10
3 Integral The Nexus truly defines the area. It is likely to be a natural Wonder of Thraxis, most of the area's creatures will reflect the Nexus, and effects are significantly altered. 8 Months 1,200 Feet 15
4 Prime The Nexus has the strength that would be found on a demiplane devoted to the Signature or opposed to the Countersignature. It still holds ties to the material plane, however, and creatures or objects that do not promote the Signature, or who embody the Countersignature can exist here. 10 Months 1,600 Feet 20
5 Legendary The area is indistinguishable from an outer plane. Entities may need to go to extraordinary lengths to survive. Artifacts can be created or destroyed here. 12 Months 2,000 Feet 25

The GM may grant Advantage or Disadvantage to mundane actions, based on whether that action is Signature or Countersignature in an area.  

Values on the Nexus Rank Table

See Personal Signature, below, for information on promoting a Signature. 

Time to Change: This is the amount of time it takes to change to or from this Rank. When a Powerful being settles down they must progress from Rank 0, to Rank 1, to Rank 2, and so on, allowing the listed time to elapse each time.

Radius Per Individual: This is the radius of the Nexus per individual who promotes the Signature at a given Rank. Combine the values for all promoters to find the Nexus's final radius. The entity who promotes a Signature at highest Rank determines a Signature/Countersignature pair's overall Rank.

Transformation Save DC: The Transformation Save DC is the difficulty of the saving throw that a creature has to make after a month in an area to avoid receiving one of the effects listed under the Signature's writeup. The exact type of saving throw varies by effect. 

SPONTANEOUS FORMATION AND DESTRUCTION

Powerful world events, such as the actions of a god or a Rage Storm can create or destroy a Nexus instantly. These events are up to the GM. 

Personal Nexuses

All entities on Thraxis have a Personal Nexus. This Nexus is comprised of at least one Signature-Countersignature pair.  This is a sort of fingerprint of the character's soul. It may never be changed except by magic with equivalent power to a Wish.

A character promotes their Signatures, and hinders their Countersignatures for the purposes of affecting a Local Nexus.  

The Rank of this Personal Nexus is equal to a creature's proficiency bonus -1. 

Personal Signature

• If the GM allows them, you become eligible for Nexus Paths related to your Personal Signature. 

• Add your Rank to the level of the spell slot that you are using when you cast a spell that is Signature for you. The maximum slot level is 9th level. As you consider learning a new spell, check with the GM to see if it will be Signature for you.

• You have Advantage on any checks required when casting a spell or using an ability that falls under your personal Signature. 

Personal Countersignature

• Subtract your Rank from the level of the spell slot that you are using when you cast a spell that is Countersignature for you. If the slot level drops below the required minimum slot level for the spell, you cannot cast it. As you consider learning a new spell, check with the GM to see if it will be Countersignature for you.

• You have Disadvantage on any checks required when casting a spell or using an ability that falls under your personal Countersignature. 

• You receive Advantage to Saving throws vs. Effects that come from your Countersignature. 

• With a touch attack, or direct physical contact (not through a weapon), you may spend a Nexus Slot  (if you have them) as a Bonus Action or a Reaction to deal damage to a creature that promotes your Countersignature. You deal 1d6 damage of your Signature's damage type (Force damage if there is no type), per Rank of your personal Nexus. 

Nexus Paths and Talents

At the GM's option, Morningstar characters receive at least one Nexus Path, from which they receive Nexus Talents under one of two progressions. These options are the Heroic Talent Progression, and the Epic Talent Progression.

Use the Heroic Progression for a slightly more down to earth campaign with a bit of wonder, and use the Epic Progression for an over-the-top campaign, where the characters are meant to be demigods. See their progression tables, below. 

Each Path has an evocative name such as "Stoneshaping Ways",  and grants Nexus Talents for each Rank that align with a specific Signature.  Every path grants effects which are level appropriate to a character -- they allow the kinds of things that could be achieved with magic items, spells, or class abilities to a character at that level, even in a non-Morningstar campaign. They may offer effects found nowhere else, of course, but they designed to be balanced.  

Paths are used to model the abilities of powerful races in the setting, but also the extraordinary capabilities of a mythic character. An example might be a fire Nexus Path called "Forged in Fire" that granted the ability to withstand and manipulate fire with your bare hands. 

Creating your own Nexus Paths

In lieu of choosing a specific premade Nexus Path, the GM may allow you to make your own. To do this, follow these steps. 

First, choose a Signature that feels thematically interesting. 

Next, choose a narrow theme for your Nexus Path within that Signature's purview. 

Then, choose 5 Spells or abilities of appropriate level for the Path's Nexus Talents. 

  • A Rank 1 Nexus Talent is approximately equal in power to a 1st level spell or a 1st-level class ability.  
  • A Rank 2 Nexus Talent is approximately equal in power to a 3rd level spell or a 5th-level class ability.  
  • A Rank 3 Nexus Talent is approximately equal in power to a 5th level spell or a 9th-level class ability.  
  • A Rank 4 Nexus Talent is approximately equal in power to a 7th level spell or a  13th-level class ability.  
  • A Rank 5 Nexus Talent is approximately equal in power to a 9th level spell or a 17th-level class ability.  

 The GM may allow you to choose level appropriate class abilities, or other affects that are at about the appropriate power level. 

Finally, look hard at the spells or abilities you've chosen for your Path, and the overall themes of it. Name it something evocative. Feel free to share your Nexus Paths on WorldsWorkshop.com, in the forums. 

Gaining Nexus Talents

In the Heroic Progression, a character has one Signature/Countersignature pair, and gains one Nexus Talent per Rank. 

In the Epic Progression, a character has two Signature/Countersignature pairs, has two Nexus Paths, and eventually gains two Nexus Talents per Rank. At any given Rank, you must take one Talent from each of your Paths when you have the option, but you may take them in any order. 

Use one of the following tables to determine how and when you gain a new Nexus Talent on your Progression. 

EPIC NEXUS TALENT PROGRESSION TABLE

Heroic Nexus Talent Progression Table

Level Nexus Talent and Rank Nexus Slots
1 Rank 1 Nexus Talent 1
2 - 1
3 - 2
4 - 2
5 Rank 2 Nexus Talent 2
6 - 2
7 - 3
8 - 3
9 Rank 3 Nexus Talent 3
10 - 3
11 - 4
12 - 4
13 Rank 4 Nexus Talent 4
14 - 4
15 - 5
16 - 5
17 1st Rank 5 Nexus Talent 5
18 - 5
19 - 6
20 - 6
Level Nexus Talent and Rank Nexus Slots
1 1st Rank 1 Nexus Talent 1
2 - 2
3 2nd Rank 1 Nexus Talent 2
4 - 3
5 1st Rank 2 Nexus Talent 3
6 - 4
7 2nd Rank 2 Nexus Talent 4
8 - 5
9 1st Rank 3 Nexus Ability 5
10 - 6
11 2nd Rank 3 Nexus Talent 6
12 - 7
13 1st Rank 4 Nexus Talent 7
14 - 8
15 2nd Rank 4 Nexus Talent 8
16 - 9
17 1st Rank 5 Nexus Talent 9
18 - 10
19 2nd Rank 5 Nexus Talent 10
20 - 11

NEXUS SLOTS

As described on the tables, you receive a number of "Nexus Slots" at specific levels. 

To use a Nexus Talent of any Rank requires the expenditure of one slot. Slots refresh after a long rest.

Some Nexus Talents, particularly those with effects that are "always on", such as one that gives you gills or an extra limb, require you to permanently expend one or more slots.  Those types of expenditures are listed under the Nexus Talent's write-up. 

ESTIMATING A CREATURE'S NEXUS RANK

For creatures with Class levels, it's easy. As mentioned, characters promote a Signature and Countersignature at the Rank of the most powerful Nexus Ability they quality for.

For all other creatures, use the creature's Hit Dice or Challenge Rating, whichever is higher, and treat them as a character with that level. Remember, of course, that even if the creature's HD or CR is over 20, that the maximum Nexus Rank is 5.

ESTABLISHING A LOCAL NEXUS

Nexuses can form spontaneously, as the result of divine, natural, or even historical events such as a great battle. The more impressive the event, the more likely a Great Spirit will settle into the area and force a shift in the Nexus, with a Rank appropriate to the magnitude of the event. As these Spirits are emissaries of the Mother Spirit of Thraxis, this type of Nexus formation can happen at any speed, even immediately. Additionally, powerful artifacts can sometimes create a Nexus around them.

More commonly, however, Nexuses form as a result of powerful (but not necessarily intelligent) entities remaining in an area for a certain amount of time. When they do so, their spirits weave with the Mother Spirit of Thraxis, and together, they begin drawing specific energies from the planes. A new Nexus is born. The Signatures and Countersignatures that they promote become those of the new Nexus, and the area's Rank gradually increases to the Rank of the most powerful being in the area.

Nexus Lords

If the most powerful being in an area brings its Nexus Rank to 4 or higher, they become a "Nexus Lord", with complete control over that region, though they may not have the intellect to take advantage of it. Creatures who promote the Nexus's Signatures will flock to the area, and their Countersignatures will change, over the course of a month, to match that of the Nexus Lord. The more creatures that inhabit a Nexus, the larger it grows. See the Nexus Ranks Table below for the details.

A Nexus Lord:

• May telepathically communicate with sentient (who don't need to be sapient) beings that they are aware of who promote the Signature within the Nexus.

• May spend Nexus Slots to cast Beast Sense on creatures anywhere within the Nexus that promote the Signature, without touching them, and even if they are unwilling.

• Regains a Nexus Slot every minute, up to his or her maximum.

• May spend a Nexus slot to change the terrain of a 40 foot square anywhere in the Nexus to difficult terrain over the course of a round, or to set up a trap over the course of 30 seconds.

• May spend Nexus Slots to cast Signature Spells at will (even if they otherwise couldn't cast spells) that appear anywhere in the Nexus. The Nexus Lord must spend a number of Nexus Slots equal to the (adjusted) level of the spell that they are casting. For example, The Nexus Lord of an Ignan region could cause fireballs to rain from the sky, cast at 8th level.

• May spend Nexus Slots to cast Dominate Beast, Dominate Monster, or Dominate Person as Signature spells at any range within the Nexus, on a creature that promotes the same Signature.

• May spend Nexus Slots to cast Wish as a Signature spell once a month, as long as the wish relates to the forces within the Nexus.

• May drain Nexus Slots from a Dominated being it can touch to use them as their own.

Nexus Wars: Challenging a Nexus

When many diverse creatures populate an area, their Signatures and Countersignatures tend to balance out over time. This, added to the time it takes to establish a Nexus, is why powerful Nexuses are not more common than they are. Once a Nexus has been established, it requires work to hold. Enemies will often rush in and try to destroy it, or more powerful beings will try to take it over.

If a more powerful being (one with a higher CR, more HD, or more Levels) who promotes the same Signature moves into the area and they stay there for one full month, they become the new Nexus Lord. The old Nexus Lord loses everything they worked for. If a Nexus Lord is defeated or otherwise leaves the area, the Nexus will diminish in Rank over the same time frame, down to the Rank of the next most powerful creature that promotes those Signatures, unless a sufficiently powerful being (Rank 4 or higher) who promotes the same Signature is available, in which case they become the new Nexus Lord.

Furthermore, when a Nexus Lord is destroyed and there's no one or nothing there to promote the Nexus's Signatures, there's often a Rage Storm that cancels the Nexus out to Rank 0 over the course of several hours.

If a new group moves in which has a different Signature, but the old (or current) Signature as its Countersignature, they begin a new Nexus overlapping the first. This new Nexus' Time to Change starts at Rank 0, and cancels out the old Signature on a one for one basis over time. The Nexus will then decay, if it was on that path, at a faster rate. Thus it is easier to destroy a Nexus than to create one.

Overlapping Nexuses

If the Signatures and Countersignatures of several Nexuses don't conflict, they can coexist peacefully, at least in theory. This is very common. These Nexuses overlap and share some or all of their territory. Therefore, a given region may have two or more Nexus Lords in control of it. These entities may or may not see eye to eye, and can sometimes go to war, even if they never go so far as to Counter each other's Signatures.

STACKING NEXUSES

Signatures and Countersignatures do not stack with like Signatures and Countersignatures when they overlap. Use the higher Rank of the two. 

CONFLICTING NEXUSES

When Nexuses with opposed Signatures and Countersignatures overlap, Signatures and like Countersignatures cancel out. In other words, if an area had an Ignan Signature of 3, and it overlapped with an Ignan Countesignature of 2, the Signature would be reduced to Rank 1 where the areas overlapped,  and the Countersignature would be completely nullified. 

This goes for Personal Signatures as well, but in a limited fashion. In such a case, the Local Nexus may affect the character's Personal Nexus, but a Personal Nexus cannot immediately affect a Local Nexus. That takes time, as described on the Nexus Effects Table.