| There's nothing unique about humans other than the fact they have not yet contracted the virus, and struggle to survive in a post-apocalyptic setting where Infected are overrun. |
| Level V Infected have only started appearing within the last 10 years, and are relatively unknown to the public. They are Infected that have survived since the start of the outbreak, and have begun to regain their humanity. Many have begun sneaking back into society. |
| The corrupted organization that watches over Stronghold with an iron fist. They act as both an internal police force, as well as an external extermination force tasked with destroying Infected nests. |
| Regular people living in the safety of the city that have no affiliation ties with any faction. Whatever business they go about, they tend to avoid the conflicts of the city and the world outside the walls. |
| A loosely-affiliated group of gangs that operate in Stronghold, they are generally are on bad terms with the Military. They deal in everything illegal, and often have internal conflicts between their various gangs. |
| A smuggler's group that lives in a walled compound outside the city. They deal with smuggling goods to people both inside and outside Stronghold, and are a form of opposition to the Military. |
| People that, for whatever reason, do not have residence inside the city, and have no affiliation ties with any faction. Some choose to live alone, while others group up with other people for safety. |