Dark Souls Online

Dark Souls Online (DSO) is the crux of the Worlds Intertwined campaign and where most of the sessions take place. It is a VRMMO game released by From Software and takes place in the world of Utlinth, a sprawling creation of hitherto unaccomplished size. After a year of its release, our protagonists started playing after they graduated from high school. The current year is 691 AB.

History
Many years ago, a recently established video game company came across an old series made by From Software before World War 3. They took on the name for themselves and decided to release a game inspired by the Dark Souls series. The new game, named Dark Souls Online, drew most of its inspiration from the first game in the series as the other two games were not recovered and restored during the development phase. It has seen some controversy due to the punishment, it applies to players who create more than 10 characters, can inflict trauma. However, From Software has won the lawsuit at every instance and has remained mostly unaffected.

Policies
From Software is very clearly trying to limit the information available about the game online on wikimedia pages and sites like Breddit and 5chan. Most information about the game available is either very general or pieced together through blogs and other smaller mediums.

They also seem to have a system in-game that will pay real money to players of a certain reputation, however further details are currently unknown.

Mechanics
This section is an amalgamation of known DSO mechanics of note, including home-brewed rules that differs from the base Dungeons & Dragons 5th Edition rule set.

Death
In Hiasel, the DSO wiki for "Dying" redirects to a page talking about Character Creation and jumps to the "Exploiting Character Creation" section that reads as follows:

' ''According to the anonymous group named "NicoTG" who are well known in the DSO community for being masochistic to the core, jumping into the game for the first time with your 11th character is described as a very painful experience, with a few people having been noted to suffer from trauma as they were trying to exploit the no character creation limit. It is regarded as the only feature of the game which encourages characters to ask others to resurrect them with resurrection spells. This is because resurrecting your old character doesn't add to your character count and becomes a painless return for your character.'''

Flanking
When a character has two enemies on exact opposite sides of him, the character is considered flanked. While flanked, enemy creatures have advantage on attacking the flanked target.

Characters that posses a Dexterity score of 15 or higher may take a feat that allows them to gain advantage against a flanked enemy.

Flash Recall
Those that have the ability to prepare and cast at least one spell may take the Flash Recall feat, that allows them to, as an action, instantly prepare a spell from their available class spell list (or spellbook, if they prepare spells from one) that they did not have prepared. This spell choice must be of a level for which they have spell slots. They then lose preparation of a different spell of their choice of equal or higher spell level. If they are multiclassed, they can only Flash Recall spells from a class that prepares spells. Once they use this ability, they must finish a short or long rest before using it again.

Inner Arcane Ability
Any character can expend any one of their spell slots to release their magical energy (corresponding to the spell slot level expended) and attempt to weave it into magic for a specific task, such as, closing a portal to another dimension, sensing magical essences in the room (one pulse of Detect Magic basically but the type of magic remains unknown), trying to overcome arcane pressure/effects that may come from staying in regions of blue arcane energy for extended periods of time, etc.

To accomplish the task they expended the spell slot to do, a successful Arcana check must be made. This can include multiple Arcana rolls based on the complexity of the task one wishes to accomplish.

Rapid Quaffing
It takes a bonus action to drink a potion yourself. Administering a potion to someone else still takes an action though (rule applies to any and all potions).

Tutorial
The in-game tutorial is available in all non-hostile situations, within a designated town or city. It scales to character level and death in the tutorial has no impact outside of it. This allows characters to test mechanics and new items.