Chapter 2: Proportion Passes & A / B / C Sets 

Created by Sarah Choi (prompt writer using ChatGPT)

Proportion Passes & A/B/C Sets — 30% Deltas

Proportion passes are the fastest way to change what a creature feels like without changing what it is. A creature can keep the same anatomy, the same silhouette family, and even the same materials, yet read as heavier, faster, smarter, cuter, scarier, or more “boss-like” simply by shifting ratios. A/B/C sets are the production-friendly format for exploring those shifts: three deliberately different proportion variants that are far enough apart to be meaningful and close enough to remain the same species. The “30% delta” idea is a practical guardrail—an instruction to push proportions enough that the differences read instantly, rather than being tiny tweaks that disappear in reviews.

This article explains how to run proportion passes and build A/B/C sets across the full creature concept pipeline—ideation → iteration → finals → handoff—so the work helps both concepting exploration and production decision-making.

Why proportions deserve their own pass

Many concept pipelines accidentally treat proportion as a byproduct of drawing. Artists iterate details, anatomy, and surface design while proportions drift in small, untracked ways. Later, when the team realizes the creature feels too slow or too cute or too humanoid, they request “make it more X,” and you’re forced into painful late-stage redesign.

A proportion pass prevents this. It isolates the biggest lever early, tests it deliberately, and produces clear options. It also creates shared language. When you can say “Variant B is 30% longer-limbed and 20% smaller-headed,” you can discuss design intent with specificity instead of vibes.

For production, proportion passes reduce risk. Animators and riggers can respond early to whether a long neck is feasible, whether a massive forequarter changes gait logic, or whether a tiny head makes facial acting harder.

What “30% delta” means in practice

“30% delta” does not mean you measure with a ruler for every change. It means you commit to visible divergence. If A, B, and C look similar in a small thumbnail, the set has failed. In creature design, subtle proportion differences can vanish once you add detail, lighting, and color. Your variants must be bold enough to survive the pipeline.

A useful way to interpret 30% is to pick 2–3 primary ratio levers and push each lever hard in at least one variant. Those levers might be: leg length relative to body, head size relative to torso, neck length, shoulder height, ribcage depth, tail length, limb thickness, wing span, or overall length.

You are not making three random creatures. You are creating three controlled experiments that answer a question: “Which proportion strategy best serves the brief?”

Proportion is the bridge between narrative, gameplay, and biomechanics

Proportion changes meaning because players interpret ratios emotionally. Large head and big eyes read juvenile or friendly. Long limbs and small torso read speed and agility. Heavy forequarters read power and dominance. Low center of mass reads stability and weight. Tall shoulders read intimidation. Compact bodies read toughness and efficiency.

Biomechanics matters too. Long distal limbs change stride and gait. Short thick limbs change acceleration and turning. Long necks create balance issues and rig complexity. Massive tails can be both a weapon and an animation cost.

A good proportion pass respects all three: narrative (what does it say?), gameplay (how does it read at camera distance?), biomechanics (can it plausibly move?).

Where proportion passes sit in the pipeline

In the ideation stage, proportion passes prevent early tunnel vision. You take a promising silhouette family and immediately explore major proportion forks before committing to anatomy details.

In iteration, proportion passes become refinement: you keep the chosen proportion strategy but test secondary ratio adjustments to solve specific notes (more menacing, less goofy, more stable, more readable).

In finals, proportion passes become lock decisions: you freeze key ratios so downstream teams can build reliably.

In handoff, proportion passes become documentation: they show what you tested, why you chose the final, and what ratios must not drift in modeling.

Building an A/B/C set: the anatomy stays, the ratios change

An A/B/C set works best when you keep the same base anatomy plan and only change proportions. That way, the team can compare “the same creature” across variants and decide what feels right.

A practical method is to start from a neutral baseline (often A), then create B and C as deliberate extremes along different axes. For example, one variant might push “speed” (long legs, narrow torso, smaller head), while another pushes “power” (shorter legs, deeper chest, larger shoulders).

Keep the view consistent. Most teams use a side view for ratio comparison and a 3/4 view for appeal and silhouette. Use a consistent ground line and consistent scale markers if the game has them.

When you present the set, annotate the deltas. Even simple notes like “B: +30% leg length, -20% head size” help everyone see the intent.

Choosing your proportion levers: a checklist of high-impact ratios

Different creatures emphasize different levers, but a few consistently produce strong reads.

Head-to-body ratio is one of the strongest. Larger heads read youth, intelligence, and sometimes comedy; smaller heads read menace, adulthood, and animalistic focus.

Shoulder-to-hip ratio controls dominance and stability. Broad shoulders read strength and aggression; broad hips read power in propulsion; narrow hips read speed.

Leg length and limb thickness control locomotion identity. Long thin legs read swift and skittish; short thick legs read heavy and unstoppable.

Neck length and tail length affect balance and animation complexity. They also add readable silhouettes at distance.

Body depth (ribcage thickness) controls “mass.” A deep torso reads strength and weight; a shallow torso reads nimbleness.

If your creature has wings, wing size relative to body determines flight plausibility and silhouette dominance.

Pick 2–3 levers to prioritize. Too many changes at once make the set hard to interpret.

Ideation stage: fast proportion exploration without detail

In ideation, keep the work cheap. You want to explore quickly and throw away freely. Use silhouettes or simple mannequin forms. The goal is to answer proportion questions before you spend time on anatomy or rendering.

Start with one or two silhouette families from your bank. Then generate 6–12 quick proportion thumbnails: some front-heavy, some rear-heavy, some tall, some low, some big-headed, some small-headed. From those, choose the three strongest, most different candidates and formalize them into an A/B/C set.

If you work in a team, this is a great moment to include animation and design leads. They can quickly flag issues like “that neck will be expensive” or “that head is too small to show expression.”

Iteration stage: proportion passes as targeted problem-solving

Once a direction is chosen, proportion passes become more surgical. You are no longer exploring wildly; you are adjusting to notes.

A good iteration proportion pass changes one primary ratio and one supporting ratio. For example, if the creature feels too cute, you can reduce head size and increase shoulder mass. If it feels too slow, you can lengthen legs and tighten torso depth. If it feels too humanoid, you can shorten arms and shift mass forward.

Maintain overlays. Keep a silhouette overlay of the previous version and compare. Proportion drift is easiest to catch with direct overlays and simple measurement guides.

This stage is also where you start to consider gear and faction dialects. But test proportions both “naked” and “geared.” Gear can hide proportion problems; you don’t want to choose a proportion that only works because armor makes it look stable.

Finals stage: locking ratios and documenting the “do not change” list

Finals are where you stop moving goalposts. Downstream teams need stable ratios to build rigs, collision, and animations.

In a final package, explicitly call out locked proportions. You don’t need to provide exact percentages for everything, but you should define the key ratios: head size, shoulder height, leg length, torso depth, tail length. If your creature’s personality depends on a small head and huge shoulders, say so.

It also helps to include one sheet showing the rejected A/B/C variants with a one-line explanation of why they lost. This protects the final decision in later debates and prevents teams from re-opening old options without context.

Handoff stage: making A/B/C logic useful to modelers and animators

For handoff, proportion passes are most valuable when they become constraints. Provide orthographic views with scale references and ground plane. Mark joint landmarks and indicate how much “squash” is allowed without breaking the read.

If the creature is going to be customized (skins, trims, faction gear), include a note on how far proportions can be pushed in variants. For example: “Cosmetic variants may change horn size and tail ornaments, but head-to-body ratio must remain within this range.” This prevents late skins from turning the creature into a different species.

If your studio uses 3D blockouts, a proportion pass can be delivered as a quick 3D mannequin or a 2D-over-3D paintover. That gives rigging a head start and makes it harder for proportions to drift later.

Production realities: how to keep A/B/C sets from becoming busywork

A/B/C sets fail when they are treated as mandatory slides rather than decision tools. The set should answer a question. If the question is already answered by the brief or by style constraints, you may not need a full A/B/C; you might need an A/B. Conversely, if the creature is a flagship boss, you may need A/B/C plus an “extreme D” to explore.

For production artists, the key is reusability. Archive proportion sets. They become references for future species and for variant trims. A well-tagged library of proportion strategies is invaluable for sequels and expansions.

Also, build alignment with tech early. If a proportion strategy requires a tail that doubles collision volume, or limbs that will clip weapons, it may be non-viable. Better to learn that in proportion passes than after final rendering.

Common mistakes and how to avoid them

One common mistake is making deltas too small. If you can’t tell A from B at thumbnail size, push harder.

Another mistake is changing too many things at once. If B changes head, legs, torso, and tail, you won’t know what caused the improved read. Control your variables.

A third mistake is ignoring camera and gameplay distance. A proportion that looks great in a close-up illustration may read poorly in the actual game camera. Test proportions at the expected on-screen size.

Finally, be careful about personality drift. Proportion changes can accidentally change temperament reads. If a creature needs to remain trustworthy, avoid shrinking the eyes too much or making the head too predatory unless the brief supports that.

A practical pipeline recipe for proportion passes

Translate the brief into a proportion question. Build a silhouette family that satisfies constraints. Generate quick proportion thumbnails to explore big forks. Select three that represent distinct strategies and formalize them into an A/B/C set with annotated deltas. Review with leads and technical partners. Choose a direction and run targeted proportion passes during iteration, using overlays to prevent drift. Lock key ratios in finals and document them clearly. Include proportion constraints in the handoff package so modeling, rigging, and skins remain faithful.

When proportion passes and A/B/C sets are done well, they speed up the whole pipeline. They make discussions clearer, decisions more defensible, and finals more stable. Most importantly, they ensure that the creature’s identity—the thing players feel in a split second—was chosen intentionally, not by accident.