Colony simulation games, a genre almost exclusively found on PC, present players with the intricate task of constructing and managing a habitat for artificial intelligence-driven inhabitants. Unlike management or city-building simulations where direct control is paramount, the core of the colony sim lies in its autonomous NPCs. These characters, whether dwarves, demons, or something else entirely, interact with their environment and each other based on simulated needs and desires. This AI-driven autonomy is the engine for the genre's signature emergent narratives, crafting tales of ambition, rivalry, and unforeseen consequences.
Tarn Adams, co-creator of Dwarf Fortress, highlights the depth of this simulation: "You watch more named non-player creatures interacting with each other over a longer period of time in a colony sim," he explains. "And you're watching them more carefully than you generally watch, say, scheduled NPCs in an RPG. It gives you a chance to really get to know the characters, and how they respond to situations both you and the game world throw at them."
The development of these intricate systems, however, is far from simple. Since the foundational work of Bullfrog's Dungeon Keeper, which established the template with its vibrant cast of demonic creatures, the genre has seen only a gradual evolution, punctuated by recent resurgences driven by dedicated development studios.
Dwarf Fortress stands as a monumental example. This two-decade-long project from Bay12 Games aims to simulate entire fantasy worlds, from terrain and history down to individual clothing choices. The game generates its extensive lore by essentially running a strategy game against itself. Its simulation is granular to an extreme, incorporating features like procedurally generated poetry, a byproduct of the cascading complexity involved in adding new mechanics. Adams notes how the development of tavern systems led to the creation of procedural instruments, which then spawned procedural music, lyrics, and even poetic and dance forms.
A key design hurdle for any colony sim is defining the player's role. Adams describes the player in Dwarf Fortress as the "official will of the fort," able to issue orders and make strategic decisions while allowing the dwarves a degree of autonomy, even the ability to disobey extreme commands. This commitment to simulating every facet of colonial life has cemented Dwarf Fortress's legendary status, though its famously steep learning curve and archaic interface present significant challenges.
RimWorld, from Ludeon Studios, offers a more accessible take on the genre, evolving Dwarf Fortress's design principles with a modern art style and a user-friendly interface. Instead of procedural generation serving as the foundation for storytelling, RimWorld is built from the ground up to generate narrative. "RimWorld is designed at every level to generate story," states Tynan Sylvester, founder of Ludeon Studios. "That’s always been the central pillar of the design, to the point that I deliberately decide every design conflict between ‘game’ and ‘story generator’ directions in favour of the latter."
This philosophy is embodied in RimWorld's AI Storyteller, inspired by Left 4 Dead's AI director. This system monitors game states through "story watchers" and triggers events via "incident generators" to create a dynamic pacing curve. The AI attempts to balance challenge with player survival, ensuring that even struggling colonies can face significant threats, as "in extreme challenge lies the greatest drama."
Despite its narrative focus, the AI Storyteller adds another layer to the colony's simulation, which already involves numerous AI agents with their own complex motivations. The interplay of building options, crafting systems, trade, weather, and environmental hazards creates a massive web of interconnected systems. Sylvester identifies "drowning in your own complexity" as a primary danger in colony sim design, emphasizing the importance of treating player learning and attention as finite resources. His approach involves making mechanics optional or introducing them gradually to avoid overwhelming players.
Communicating the intricacies of these simulated worlds to the player is another significant development challenge. Simon Roth, creator of the colony sim Maia, notes that presenting complex AI information clearly and unobtrusively has been the game's biggest hurdle. Maia, which draws inspiration from Dungeon Keeper, simulates its alien world at a granular level, with colonists having around 50 distinct needs that influence their mood, from social interaction to ambient lighting.
To address this, Maia utilizes its 3D engine for detailed animations to convey obvious colonist emotions. For more nuanced issues, colonists can send players emails, often lengthy procedural messages detailing their state and even suggesting solutions to problems. "If they’ve got a skill for a thing and they spot a potential problem in the base, they can suggest doing something to the player, and the player can either give them a yes or no answer," Roth explains, illustrating the colonists' self-awareness.
Despite its nearly 30-year history, the colony sim genre remains fertile ground for exploration. Recent titles have pushed the boundaries of simulation and emergent storytelling, yet the inherent challenge remains: the more detail developers include, the harder it becomes to ensure that detail is effectively communicated and appreciated by the player. Like any storytelling medium, the ultimate success lies not in the sheer volume of content, but in its engaging presentation.