Here’s a quickie, five different aspects of the Random Number God covering five of the eight divine domains of 5e. Nothing to do with Halloween, except in that the Death Domain is covered. I guess that’s spooky.
Death Domain: Aspect of Despair
The aspect of despair is represented by a d20 showing the 1. This aspect is prayed to for revenge on others and to bring ruin onto foes. They believe that the RNG is ultimately a force of chaos and entropy, that sooner or later all shall be struck down by a critical fail, and that one can only hope to enjoy the ride while it lasts by having inconvenient others targeted for smiting first.
Knowledge Domain: Aspect of Statistics
The aspect of statistics is represented by a bell curve. They hold the unorthodox belief that the RNG is best represented by 3d6 instead of 1d20 (some even more unorthodox sects believe in 2d10, and are represented by a slightly different bell curve, which is usually only distinguishable from the 3d6 curve by those initiated into the secrets of the aspect of statistics). They believe that the RNG can be studied and understood to determine predictable results over a long period of time even though it is chaotic and unreliable from moment to moment.
Life Domain: Aspect of Stability
The aspect of stability is represented by a d20 showing the 10. These hold the belief that the RNG does not favor anyone in particular, that in the end everyone’s results average out to 10 (technically 10.5, but that’s less pithy and looks terrible as a symbol). They believe there is an inherent justice and fairness to the RNG. They are fiercely divided between the Take Ten sect, who believe that since the RNG averages out to about 10 it is fair to assume any given result is a 10, and the Traditionalist sect, who believe that assuming a result of 10 is blasphemy against the holy average present in the rolling of the d20.
Trickery Domain: Aspect of Chaos
The aspect of chaos is represented by a d20 with a blank face. The aspect of chaos believes that the RNG giveth, and the RNG taketh away, and none can predict when or where it will do one or the other. The RNG is a capricious master, and the sect of chaos embraces the madness. They believe that any attempt to understand, predict, or even curry the favor of the RNG is futile, and all you can really do is learn to roll with the punches.
War Domain: Aspect of Conquest
The Random Number God’s aspect of conquest is represented by a d20 showing the 20. This aspect is prayed to for critical success needed at key moments, especially in war. This aspect believes that the fortune of the RNG is a direct sign of its favor, and that the right to rule derives from this. In other words, people who are on a lucky streak have been chosen for victory by the Random Number God (regardless of whether they’re winning or losing due to bonuses).
I’m not sure what to do about Nature, Tempest, and Light, which all represent various natural processes. You can jolly well roll on a random table for the current weather or for nature-based random encounters in the wilderness, so it’s not like the RNG doesn’t have a foothold here, but it’s not quite as fundamental an aspect of the RNG as the other five.