DeadOS, an outbreak simulator that delves into the minutiae of zombie apocalypse scenarios, demonstrates that initiating a successful undead pandemic is a complex undertaking. Developed by indie creator Benn Powell, known for his work on Resident Evil mods, the simulation sandbox draws inspiration from the iconic opening of Resident Evil 3, focusing on the immediate aftermath of an outbreak rather than the survival gameplay that typically follows.
Powell began developing DeadOS in 2019, with the COVID-19 pandemic influencing its design, particularly its focus on the R rate – the ratio of people infected by each zombie. The simulation allows players to set numerous parameters, including city size, population, the presence of armed citizens and police, virus transmissibility, and zombie speed. Once configured, the simulation unfolds procedurally, depicting the spread of the outbreak across a 3D cityscape. While not a traditional game with specific objectives, DeadOS offers a fascinating look into how such a scenario might realistically play out.
Initially, DeadOS was a simpler infection simulator, but the introduction of elements like weapons and police added layers of complexity. Powell incorporated human factors such as panic and hesitation, reflecting realistic responses to danger. Even with these considerations, the simulation revealed that a single slow zombie often struggles to initiate a widespread outbreak. Civilians tend to flee, and police intervention can quickly contain a lone undead threat. The simulation often fails to propagate an epidemic from a single patient zero, especially with traditional, slow-moving zombies. As Powell notes, "If you just let the simulation run, it will fail, because it's just one [zombie]."
To effectively seed an outbreak, DeadOS suggests that multiple infection points are crucial. When an epidemic starts in two or more locations simultaneously, fleeing survivors can inadvertently carry the infection to new areas, leading to a more widespread crisis. The speed of the zombies also plays a significant role. Powell found that faster, more aggressive zombies, akin to those in 28 Days Later, are far more effective at spreading infection, especially when coupled with rapid human-to-zombie conversion times. "They [can] go as fast or faster than people," Powell stated.
The simulation also offers insights into human behavior. Powell observed that more courageous individuals are more likely to confront the infection, but this also leads to higher mortality rates. Conversely, carrying a weapon significantly increases a civilian's chances of survival. The simulation suggests that a combination of cowardice and firepower might be the optimal strategy for personal survival.
In a population of 4,000, the simulation indicates that around 250 traditional zombies are sufficient to overwhelm containment efforts without external intervention. Players can choose to passively observe the unfolding events or actively control a specific NPC, guiding them through survival tasks such as combat, building barricades, and scavenging for resources. Although DeadOS runs in what appears to be real-time, it is fundamentally a turn-based game with rapid turn progression.
Players can also choose to call in direct military intervention, a feature that sees helicopters deploy squads to systematically sweep and secure the city. DeadOS has been in development for approximately seven years, with nearly five of those spent in Steam Early Access. Powell intends to continue its development, with plans to implement Steam Workshop support for custom city designs and the addition of more detailed institutions like hospitals and quarantine systems. Powell's ultimate ambition is to create the definitive zombie outbreak simulator, a "Dwarf Fortress of undead Armageddon," driven by his desire to create the game he always wanted to play but found did not exist.