OASIS

The OASIS (Ontologically Anthropocentric Sensory Immersive Simulation) is a MMOSG (massively multiplayer online simulation game) created by James Halliday and Ogden Morrow of Gregarious Simulation Systems. While starting as an online gaming platform, the OASIS gradually evolved into a globally networked virtual reality world that most of humanity now uses on a daily basis. It will go live on December 8th 2025.

History
It co-evolutionized the entirety of gaming and made up for all of GSS' 10-or-so years of lost revenue they spent creating it. The unprecedented success of the OASIS made Halliday one of the wealthiest people in the world. After Halliday's death the OASIS continued to evolve and grow in popularity, protected from takeover attempts and legal challenges by the ironclad terms of Halliday's will and the army of lawyers he had tasked with administering his estate.

Gameplay
While obtaining and booting up the game costs only 25 cents (one quarter) to use and operate (an homage to the video games of the 1980s which only required one quarter to run per game), in-game vending, travel between worlds and zones, and almost everything else costs additional in-game fares.

Worlds and Zones
The universe of the OASIS is split into 27 sectors each 10 light hours across, arranged like a Rubik's cube. The sectors have zones that can be any shape and size, and each has different rules/flags. Zones could allow or prevent magic, technology, PvP (Player vs. Player), teleporting, communications, and more. For instance, Ludus, the schooling planet, is a no-PvP zone. The worlds within OASIS can also have different settings. It is described that Ludus is always day, Neonoir is always night, and Archaide's sky never changes with a volcano always on the horizon. Planets can be player built, owned, and colonized, or created by the developers. Experience and leveling
 * OASIS Worlds and Zones