This is something I wrote to help explain the perceived strength of various powers relative to one another. I haven't contributed much to the site, so I thought I should add something for everything I have taken.
Have you ever paused to consider why there is a greater amount of influence by on power over another from prime world to prime world? Why is it that Zeus is venerated as the supreme deity with near limitless power, while Thor, a power with a similar portfolio, is subordinate to Odin, a god of war and wisdom, which are the same portfolio of Zeus’s daughter, Athena? Why is it that Tyr is viewed as an intermediate power on one prime world, while another views him as a greater power?
The answer lies primarily not in the powers themselves, but their faithful. Aside from the divine spark, powers draw strength from the strong emotions from mortals upon hearing the name of a deity. The joys of a new birth, the thanks given for a harvest that will keep starvation at bay for another winter, the rage and desire for revenge after seeing family slaughtered by goblins, or the fear of ritual sacrifices at the hands of cultists all evoke very strong emotions. For this reason, fear of the goddess Kali sustains her as much as active worship by a barmy cultist.
The more veneration given a power by the faithful, the more divine influence that power can exercise. Obviously, these strong emotions are exactly what priests are able to conjure through worship sessions and why deities with identical portfolios often compete for access to the faithful. This competition can be cordial with persuasion by priests the only tool used, or it can be open hostility.
To limit access to some prime worlds or portions of worlds, some deities will form a pantheon to collectively promote a culture that encourages worship of the pantheon. Individually, very few powers could limit access by another power. However, a group of powers (such as the Norse pantheon) could pool their strength and create an effective shield, barring the entrance of even a greater power (such as Zeus). There is certainly debate as to whether Odin could prevent Zeus from accessing a given prime world, but how much divine attention does any one world merit when there are potentially thousands? The collective strength of a pantheon allows the powers to hold a stake in multiple worlds without sacrificing too much individually.
This is where some of the politicking between the powers comes into play. Because of the enormous resources that one power must use to directly confront another, such confrontations are very rare and the topic of much discussion among greybeards. More frequently, actions are taken against agents of a rival deity. This frequently happens through layers of intrigue and subterfuge that confuse even the most learned scholars. For this reason, very few mortals ever come to truly understand why escorting a young woman home after work can impact the multiverse more than recovering a holy avenger stolen from the tomb of a great paladin of Tyr. It often takes years, decades, or even centuries to uncover the designs that the powers have for the planes.
Good work![Smiling Smiling](sites/all/modules/smileys/packs/Example/smile.png)
This fits pretty much how I've always seen the powers.
It could be interesting to debate how exactly powers keep one deity away from "their" parts of a world if that "intruder deity" really wants to get in.
There could be much more than politics. I like the idea of that "divine shield" you mentioned, and there could be more: Maybe a power intruding into a pantheon's portion of a world could actually be influenced by the, well, "pantheon vibrations"
and thus would prefer all by itself not to get there, because it wants to keep its individuality.
Young powers might not even realize that and only understand what's happened to them when it's too late to react. There could even be something like an assimilating "borg pantheon".
Also, a power fighting against such influence might have to split up a part of itself to protect its existence against the influence. That could create an entirely new deity actually fitting into the existing pantheon...