We don't know who or what created this Rule of Divine Governance, but it seemed to work that by gaining more worshipers, one gained more power over a realm. If one had overwhelming divine influence by way of a large worshiper base, then this Higher Power could strip another of their connection to a Sphere. Said power, disconnected from their worshipers, suffers a reduction in their divine power. Ares used his overwhelming influence to take over several worlds. When I and others learned of this, we had no choice but to create our own religion and attract worshipers.
- Arcana, from a rune stone inside Achamâz - "Divine Influence"
Divine power is the strength of a Higher Power in relation to others higher powers. Divine power is gained by acquiring followers in the Mortal Systems. The Divine Rank of a higher power determines how many domains they can have when they reach a new Power level. This is a starting number, because gods, fiends and anything considered a Higher Power can acquire domains by utterly defeating another higher power or primordial lord and taking one of their domains or in the case of primordial lords, their energy and convert it into a domain. This tactic of taking a domain by killing another is more commonly done by evil and neutral beings. A goodly higher power would not start a conflict on the pretext of acquiring a domain by totaling eliminating another. Ares was the first god to crush another upstart deity and take one of his domains, along with the other god's entire worshiper base. When Ares went from a demigod to a minor god in less than a fortnight, the others took notice. Arcana would say that it began a race for mortal followers among the gods, with even some of the Creationists relinquishing their creationist powers to take on mortal followers.
Rule of Divine Conquest
This aspect of Divine Power gives one the divine power of another. It comes from delivering the killing blow to a Higher Power, either by another Higher or even by a mortal.
On 3 Bliss 9111 GE, a trio of Covenant heroes took down a primordial behemoth named the Nine-Tongued Worm. Having delivered the killing blow, and by the Rule of Divine Conquest, the Covenant hero Phalgas acquired some of its power.
Sometimes, when a god is killed by a mortal, that mortal takes his place. This usually comes about if the mortal is of the right mind to serve in such a capacity, and if there is a need of having another Higher Power.
In 588 HE, the orc hero Gruumsh killed the goblin god Maglubiyet. With his death, Gruumsh took his tyranny domain, becoming a god by conquest.
Once you have given up life, you also give up godhood and release the power of your domains to Set. He will get stronger with your death, he has the right to select part of you as his own.
- Hades, to Jurmalon imprisoned in the Black Chariot - "Divine Release"
Set killed Jurmalon on 13 Temporal 985. With his death, Set took Jurmalon's divine power, bolstering his mastery of the Darkness Domain.
Rule of Divine Demotion
If a Higher Power loses too much divine power, which usually means their worshipers are being decimated or they have moved on to other gods, then they will be demoted in power. If they are reduced below cult power, then they are no longer a god, and no longer an immortal.
When Aslauthroa fell, the centralized nature of the Church of Talos crumbled. This reduced Talos's influence, eventually removing him from the ranks of Higher Powers. Juiblex is another that was demoted for lack of believers.