A brief explanation:
This is a brief explanation of why I'm asking the question about available lore in D&D related to the origins of good/evil being associated with dark/light.
Two other GMs and I are creating three separate epic adventure campaigns that will run concurrently. Each campaign will have three core players starting at levels ranging from 15-17 (20 before the end). There will also be several committed drop-in players who will play in short stretches with PCs ranging from levels 4-15. In addition there will probably be random players dropping in for single days with any level up to 15.
These three campaign "teams" will eventually meet up over a three day weekend marathon session in which all the nine core PCs (and possibly one or two other PCs) will be united in-game and each GM will take the helm for one full day of gaming, while the other two GM's provide support (and prepare snacks and dinner). This final 3 day marathon session will be the culmination of the three teams' adventures and will establish much of the foundation of the D&D world in which the three of us GM's will run our future campaigns.
What the world will end up looking like:
This is not something I can answer fully at this point as some of what the world will look like will be determined by the choices the PCs make in their adventures. There are infinite possibilities. However everything is on the table, and the overarching story lines of the three GMs will subvert some concepts and events in the D&D multiverse that are generally considered fixed. For example one of the GMs is currently considering a campaign that takes their team of PCs on an epic journey through time, space and a considerable amount of planar travel and reestablishes the relationship between Dragons and Giants, essentially recreating that history into one where dragons and giants unite to defend the planes against encroaching demon lords and possibly other planar beings. As you can imagine this will upend many assumptions currently in the game.
The overarching story line of the campaign I will GM will result in the subversion of the established connections between good and light, and between evil and darkness. In the world that comes after the events in this campaign evil will tend to associate with light and good will tend to associate with darkness. Demons will live in planes of light. Angels will live in darkness. The Underdark will be the home of caring elves with forests of mycelium and brilliant underground mushroom gardens. The sun will be seen as the harbinger of death. Night will be a haven of safety from the evil that lurks in the day. These are just a few examples of the impact this adventure will have on the worlds and planes of D&D.
There are many details to establish for this world which we are tentatively calling "Endworld," but hopefully this gives you a taste of what it will be like and how different it will be from the current generally established worlds of D&D. In Endworld the changes we establish will affect all time, all planes and all worlds of existence. In short it will encompass the whole of the D&D multiverse because the campaigns themselves will encompass the whole of the D&D multiverse. The shifts we create in this epic three-part campaign will be something we can apply to any world, any plane, any pantheon, throughout all history in the D&D multiverse.
For example if we were to pick up the original Ravenloft module from 1983 we would be able to convert it to Endworld, just as we would be able to convert the most recent Forgotten Realms adventure campaign. Likewise many of the planes will see vast changes, most notably the Nine Hells will be bathed in light with castles of gleaming crystal. All of the D&D multiverse, from its very beginnings to this day will be open to use in Endworld. Of course non-5e material will need other converting as well, but we've done this in the past on our own or by purchasing conversions online.
Why I need various lore from any and all points in the D&D multiverse:
In order for this extensive campaign to be successful I will have to design an adventure that weaves through many worlds, planes, and times. The associations of dark/evil and light/good cannot be reversed if I don't know where they began. Which narratives established this duality, which gods cause them to endure, which ongoing cosmic struggles epitomize the duality and in a way aide them in persisting? In short I need to know as much lore as I can from throughout all D&D settings concerning the establishment of dark being associated with evil and light being associated with good.
Where to go from here:
I hope that this establishes clearly what the information is that I am seeking and why I asked this question. I understand that I asked the question without providing enough background information and I take responsibility for that miscommunication. In light of some of the objections which have arisen I have some solutions that I hope will suitably address the missteps that I have made and provide a question that meets the expectations of this community.
I will provide background info and state clearly what my goal is. Thanks to @SevenSidedDie introducing me to the XY problem, I recognize that I posted an almost perfect example of what not to do when trying to avoid the XY problem. My original post addressed what I believed was the solution to a problem and I never posted what the problem actually was that I was trying to solve.
I will break up my question into smaller more manageable questions. I see that asking a question with a broad range of possible answers the way my original question did is not appropriate for this site. @ObliviousSage and others have made very good points about the breadth of my question being to vast. I respect that position and will instead ask a series of specific questions that focus on individual worlds within D&D or on individual planes or pantheons. This will narrow the focus of possible answers and will, I hope, make these questions suitable for RPG SE.
I will clarify what it is I'm seeking. Instead of posing a general question like I did in my original post, referencing "D&D lore" I will ask more pointed questions that have specific answers. For example, Which gods in the Forgotten Realms are involved in mythology concerning the duality of light and dark and good and evil?
I will avoid broad opinion-based statements. In my original post I think my statement that dark/light and good/evil are tiring was irrelevant and unnecessary to the question as a whole. In this case I think my personal opinion got in the way of asking a question. I will leave that and similar statements out of the question.
I will be as clear as I can be with my wording. I think some of my original wording was not very clear and may have created some miscommunication on my part. I will strive to be very clear in how I phrase the relevant info and question.
Thanks,
I hope this addresses the concerns that came up with the original question. This approach will mean that I will be posting several distinct but similar questions. In order not to clutter the question time-line with a bunch of these questions I will space them out over several weeks.
