Reference
Settings: many, see also Effulgence worlds and this old Alicornutopia thread
Main templates: Bell, Joker, Sherlock, Miles
General info: A guide to Effulgence, including content warnings, may be found in How to Read Effulgence.
Prerequisites: Optionally, Luminosity and Radiance by Alicorn. Effulgence is set after Radiance.
Spoiler warnings:
Subcontinuity [to be added] contains major spoilers for Ender's Game.
Subcontinuity "an art project" contains major spoilers for the Vorkosigan saga.