Milky Way, distant future

Quickstart is not recommended. Humans span most of the Milky Way, and use their vast technologies to populate new host planets far away and established vast sprawling megastructural cosmic supercities as central hubs for transport, economy, and government across the galaxy. Many of these hubs also develop large urban-like areas filled with semi-dense housing plans and communities for people to live in and work from. These hubs also usually have one large or several smaller encapsulating structures used to simulate an atmosphere. While the story starts in the Milky Way, other galaxies have inhabitants as well and may rarely visit other galaxies. By this point, almost half of all habitable planets are full of life, many of human origin, but some from other notable spanning species like the Kryýv. Some species, like the Rax, pose a threat of to the established unity between species. Some space cities, such as most of the super city hubs, are artificially created planet-sized celestial bodies which are built around a sun with a natural orbit. These megastructures can last for billions of years with the right materials and maintenance. The social class system is split into 4 tiers. In order of income from least to most, it goes: 3rd-class, 2nd-class, 1st-class, and 0th-class. 1st-class and 0th-class have vastly more income than all previous classes respectively.