Understanding TTRPG Design Through Four Overlapping Scales

When discussing tabletop RPGs, terms like “crunch” or “narrative focus” frequently arise. While useful, these discussions can become muddled, lacking a structured way to examine what makes each game unique. To frame this conversation, we can use a model of four overlapping scales: granularity, modularity, connectivity, and fidelity. Each of these represents a distinct axis of design, shaping how we experience and engage with games.

Let’s break down each scale and explore how they influence play.

1. Granularity (aka “Crunch”)

Granularity measures how detailed a game’s mechanics are. High-granularity systems, like GURPS or Pathfinder, offer intricate rules that cover a broad array of situations, from combat maneuvers to nuanced skill checks. On the other hand, low-granularity games like FATE or Lasers & Feelings simplify mechanics, focusing on streamlined gameplay. The level of granularity directly impacts pacing and player focus, influencing whether the experience feels like a tactical simulation or an improvisational story.

• High granularity: Provides clarity and structure but often slows down play with extensive rules. These systems excel when precision and fairness are crucial, such as in detailed simulations or competitive campaigns.
• Low granularity: Prioritizes narrative flow and accessibility, sacrificing precision for speed and creativity. Minimalist rules can empower players to improvise and lean into storytelling.

Granularity’s importance depends on player preferences. High granularity caters to those who enjoy mastering detailed mechanics or exploring tactical depth. Conversely, players seeking fast-paced, story-driven sessions might prefer the flexibility of low-granularity systems.

The interaction between granularity and other scales is key. For example, high granularity often pairs well with high fidelity when realism is a goal, as in games like Call of Cthulhu. However, it might clash with high connectivity when detailed mechanics interfere with narrative immersion.

2. Modularity

Modularity examines whether a game’s mechanics can function independently or integrate additional subsystems without disrupting the core rules. While modular games excel in flexibility and customizability, tightly integrated systems maintain consistency and reinforce their themes.

• High modularity: Games like Dungeons & Dragons thrive here, allowing the addition of feats, crafting systems, or optional rules without breaking the foundation. This adaptability has enabled D&D’s long-lasting popularity and its ability to support various playstyles and genres.
• Low modularity: Systems like Blades in the Dark or Apocalypse World have tightly integrated mechanics that are harder to separate or tweak without losing the intended experience. These games rely on focused systems that ensure every rule reinforces the theme.

High modularity supports flexibility and customization, enabling GMs and players to tailor the experience to their preferences. This is especially valuable in long-running campaigns or for groups with specific narrative or mechanical interests. In contrast, low modularity ensures a unified play experience where every rule contributes to the game’s thematic and narrative goals.

For example, a modular game like GURPS allows players to create entirely new genres or settings, while a low-modularity game like Blades in the Dark deeply intertwines its heist mechanics with its narrative, making it harder to adapt without losing its essence.

3. Connectivity

Connectivity refers to how closely the game’s mechanics link to its setting or story. High connectivity fosters immersion, embedding players deeply in the game world. However, low connectivity can allow the same system to support wildly different stories.

• High connectivity: Games like Apocalypse World tie their mechanics directly to narrative beats and thematic elements. Moves in these systems feel intrinsically tied to the world and its flavor, creating a strong sense of immersion.
• Low connectivity: Systems like Savage Worlds or GURPS use universal mechanics designed to adapt across genres, settings, or styles. Their flexibility allows for a wide variety of stories but can result in a less immersive experience.

Mechanics in high connectivity games are designed to evoke the tone, mood, and flavor of the setting. Conversely, low-connectivity systems prioritize flexibility, enabling creators to use the same mechanics across multiple genres and settings.

An excellent example of high connectivity is Call of Cthulhu, where the Sanity system deeply reflects its themes of cosmic horror. In contrast, Savage Worlds or GURPS offers flexibility, allowing players to jump from pulp adventure to hard science fiction without needing entirely new rules.

Call of Cthulhu and Pendragon (also from Chaosium) also reflect an interesting intersection: low connectivity systems can be developed into high connectivity games. BRP is a generic roleplaying system that both use. However, their implementations are high connectivity with the way Sanity is integrated in CoC and the way morality is directly tied into the mechanics for Pendragon.

4. Fidelity

Fidelity measures how well a game’s rules express its core genre or themes. High fidelity creates genre-rich experiences but may alienate those unfamiliar with its style. Low fidelity broadens accessibility, making it easier to approach but sometimes losing specific thematic weight.

• High fidelity: A game like Call of Cthulhu uses its Sanity mechanics to evoke the horror of cosmic dread, weaving the theme into every aspect of play.
• Low fidelity: Systems with generic mechanics, such as FATE, prioritize versatility over thematic depth. While these games can be tailored to fit many genres, they may not evoke specific moods as strongly as high-fidelity systems.

High fidelity creates genre-rich experiences but may alienate those unfamiliar with its style or unwilling to embrace its thematic focus. Low fidelity broadens accessibility, allowing games to be more flexible and replayable across genres.

The impact of fidelity on play can be profound. A high-fidelity game like Cthulhu Dark leverages simplicity to heighten its horror themes, while a low-fidelity system like FATE allows players to create settings and genres tailored to their specific desires, at the expense of specific thematic resonance.

Clarity: Distinguishing Connectivity and Fidelity

Connectivity and fidelity are closely related with some overlap, but are nevertheless distinct aspects of TTRPG design. Connectivity is focused on how mechanics push the narrative forward, how they shape and influence the story. Games with high connectivity, like Apocalypse World, have mechanics that tie directly to the development of the story and its characters, driving the narrative momentum.

Fidelity, however, is about how well a game’s mechanics represent its core genre or theme. High-fidelity games, such as Blades in the Dark, reinforce the setting’s dark, gritty nature through mechanics like stress and trauma, which emphasize the risks and emotional weight of the game’s actions. Morality and corruption mechanics are also often high fidelity, but also quite often only drive the narrative forward by their interpreted consequences and future play rather than a direct high connectivity narrative mechanic (Vampire: The Masquerade presents a good example).

Fidelity isn’t just about advancing the story; it’s about enhancing the mood and emotional engagement with the genre or game concept itself. The key difference is that while connectivity is about narrative flow and how the mechanics influence the direction of the story, fidelity is about how deeply the mechanics immerse players in the themes and atmosphere of the setting.

Why These Scales Matter

Each game balances these scales differently, creating unique experiences for players and GMs. For example:

• A gritty cyberpunk game might lean heavily into high granularity, high connectivity, and high fidelity to emphasize its dystopian tone.
• A pulpy adventure game might favor modularity and low granularity for fast-paced, action-packed play.

Games that deliberately subvert these scales often create surprising or innovative experiences. For instance:

• A modular, low-fidelity system like early D&D used in a thematic setting like Dragonlance.
• A rules-lite, high-fidelity system like Cthulhu Dark, where simplicity reinforces the core horror theme.

By recognizing how these scales interact, designers and players can make intentional choices that suit their desired play experience. Balancing granularity, modularity, connectivity, and fidelity allows for rich, varied TTRPG experiences that cater to diverse preferences and playstyles.

What do you think about this model? How do you see these factors? Poke us on Bluesky and let us know!