"An idea has no heft but it can move mountains. An idea has no authority but it can dominate people. An idea has no strength but it can push aside empires. Knowledge is the greatest tool of the mortal mind, outweighing anything made by mortal hands. Before anything can exist, the idea must exist.”— An aphorism and common prayer of Oghma's faithful
This section of the Crucible of Creation's Player's Handbook is devoted to the various custom rules and play systems deployed for use within the campaign. While many of them leverage off of the source material produced by Wizards of the Coast and their source material, a significant portion of these were developed by third parties or modified directly by the DM's and staff of the campaign to better serve the intended genre and themes being presented within the narrative.
The 'Crucible of Creation' is an actively evolving setting that openly embraces the fact that change is inevitable and that the natural laws, rules, and fate itself can bend to the will of determined individuals given enough time, effort, and determination. Many of the systems employed are intentionally experimental and prone to tweaks and adjustments in order to adjust the difficulty and narrative to fit the setting.
The DM will do his best to avoid situations of ret-conning, but expect some fluctuations and flexability with these systems as they get explored and their edge-cases get tested. If a change fundamentally impacts your enjoyment of the game, please raise those concerns with your DM sooner rather than later. Feedback and response is important in making adjustments as part of this experimental, in-development effort.