Domains
Domains are Esoteric energy given physical form. They are specialized techniques (denoted with a (Do) type next to the ability) which operate uniquely from instance to instance, but generally share a few similar characteristics.
These standard characteristics typically include the following;
Radius
An area of effect whose radius is equal to a number of 5ft increments equal to the key ability score modifier of the invoking creature plus their number of Hit Dice, this is known as a Standard-Radius Domain.
Barrier
An enclosing barrier around the area of effect, this barrier has statistics similar to a Wall of Force, but the interior has a hardness is equal to the hit dice of the Invoker, the exterior has no hardness, and the hit points is equal to the number of hit dice the invoker possesses multiplied by their key ability modifier, known as a Barriered Domain.
Additionally, the barrier can be transparent or opaque, denoted as an Opaque Barriered or Transparent Barriered Domain.
Barriered Domains remain stationary, allowing the invoker and all other creatures within it to move about the area of the Domain. Barrierless Domains are centered on the invoker and move with them.
Distributive
The ability to distribute the effects of abilities and techniques to all creatures within the domain by targeting the Domain itself, which is considered a Distributive Domain. The invoker may be immune to this distribution, if they so wish.
It is possible for a Domain to have all of these abilities and more, it is also possible for a Domain to have none of these characteristics.
Domains typically require a Full-Round Action to invoke, and Concentration to maintain, but may be dismissed as a Free Action.
Domains are treated as spells with an effective level equal to ½ the Hit Dice of the invoker of the Domain, and a save DC of (10 + ½ the Hit Dice of the invoker + the invokers key ability score modifier) if not otherwise specified.
Additional Domain Characteristics
The characteristics Domains can possess are as stranger and varied as the individuals who invoke them, and listed below are a few of these characteristics;
Innate Spells
The effects of spells may be imbued within the area the Domain affects. These spells use the spell level and DC of the Domain itself, and the number of Hit Dice of the Invoker as their Caster Level, when determining their effects. If the spell is an area of effect, it is generally centered on the Invoker unless otherwise stated. Innate Spells cannot affect outside of the Domain unless otherwise stated.
Domain Manipulation
Domains may be modified through Binding Vows the same way that other Esoteric effects can be. Binding Vows typically affect the Innate Spells of the Domain, however they can be modified to affect other features of the Domain.
The standard characteristics of a Domain can be subject to Binding Vows. Adding or removing the enclosing Barrier, the Distribution effect, or a portion of the Radius (half or double) grants + or – a number of effective metamagic levels equal to the key ability modifier tied to the Domain for each characteristic added or removed.
Domain Clashes
If two creatures invoke their Domains simultaneously, or a creature invokes their Domain within an already existing Domain, a Clash occurs.
Clashes are resolved by the more developed and powerful Domain taking precedence. This is determined by the effective spell level of each Domain. If they are equal, then both Domains are dispelled with all associated costs consumed.
If a Domain does not have an enclosing Barrier, then it does not Clash when used against another Domain; the effects of both simply overlap.