When Fewer Verbs Make a Richer Game — The Lineage of Subtractive Design

Introduction

When people talk about puzzle design, attention drifts toward what to add: a new verb, a new gimmick, a new hazard. But look across the history of thinking puzzles and the games that stay played for decades are built by subtraction, not addition. One verb, a few lines of rules, and yet tens of hours to finish. I call this paradox of 'few but deep' subtractive design.

This essay traces the lineage from the 1982 Sokoban to 2020's A Monster's Expedition, games that deepened difficulty without adding verbs. As the central design argument of the verb-minimalism series, I want to ask, from a maker's view, why subtraction makes puzzles deeper and where that depth comes from. Subtraction is not abstinence; it is a tool for raising the resolution of design. Deciding what to cut is also a declaration of what to keep.

Sokoban as a Minimal Set — The Reach of a Single Push

In 1982, Hiroyuki Imabayashi at Thinking Rabbit founded a genre with a single verb. All you can do is push. You cannot pull, you cannot lift. A crate shoved against a wall is lost forever. That one-directionality is the source of Sokoban's difficulty. The original had no undo at all; a mistake meant restarting the level. I wrote about the weight of punishing trial in The Ethics of Undo, and subtractive design and failure design are really two sides of one coin.

The constraint of a single push makes the state space astonishingly rich. Each added crate multiplies placements exponentially. Because the verb is scarce, the player must read every corner of the board. Add a second verb and allow pulling, and many levels collapse at once. Subtractive design rests on this delicate balance. As I noted in The Lineage of Meta-Puzzles, Sokoban's push verb became the template for the whole genre.

What impresses me replaying Sokoban is that this minimal set has not aged in forty-four years. The graphics are plain, the sound nearly absent, yet the weight of a single move rivals any modern blockbuster. The strength of a minimal set is the strength of a skeleton that survives stripping away ornament. As a starting point for subtractive design, nothing is purer.

Snakebird and Stephen's Sausage Roll — Drilling Into One Verb

In 2015, Noumenon Games' Snakebird swapped Sokoban's push for a snake body that grows as it moves. You only steer the direction. But because the body links cell by cell, your own length becomes both obstacle and platform. Add gravity, and a body lengthened by eaten fruit falls into unexpected dead ends. The verb is effectively one, yet the moving part that is your own body explodes the state space. This is the classic move of subtractive design.

In 2016, Stephen Lavelle's Stephen's Sausage Roll pushed the drilling-into-one-verb idea to its limit. You only roll and grill sausages. The vocabulary, a fork direction and movement, barely differs from Sokoban. Yet it is regarded as one of the peaks of thinking puzzles, and ten years after its 2016 release designers still pass it along. By running few verbs through one deeper axis, rotation, the combinatorial space grew dramatically.

What Snakebird and Stephen's Sausage Roll share is multiplying not the verbs but the interpretations of a verb. The snake body, the sausage's facing. Neither added a new button; both put the side effects of an existing verb at the center of design. Drilling into one verb gives the player reassurance that no more rules are coming and the tension of still not solving it. The pleasant severity of subtractive design is born here.

A Monster's Expedition and Bonfire Peaks — Subtraction Meets Story

In September 2020, A Monster's Expedition, led by Alan Hazelden at Draknek & Friends, laid exploration and story over subtractive design. The verb is only knocking down logs to cross. A felled log becomes a bridge; roll it to reach another island. So far it is pure Sokoban lineage, but the game connects islands into a continuous world and scatters a humorous story across museum exhibit labels. On the clarity won by subtraction it layers the joy of wandering.

In September 2021, Corey Martin's Bonfire Peaks took a one-verb puzzle of carrying boxes and burning them on a fire and layered on the feeling of loss and letting go. Climbing a quiet voxel mountain, the player burns their belongings one by one. It shares lineage with A Monster's Expedition through Draknek's publishing, but Bonfire Peaks is more introspective. Subtractive design can turn dry, yet here subtraction itself is the theme.

These two show that subtractive design is no enemy of emotion. Narrowing the verbs concentrates the player's attention on the board's details. In the margins of that focus there is room to slip in scenes, a museum joke or the smoke of a fire. It differs from the lineage in Turning Looking into Play, but it is continuous with it in that fewer verbs raise observational resolution. Subtraction prepares the quiet needed to tell a story.

Why Subtraction Deepens — Combinatorial Explosion and the Pressure to Read

The first reason subtraction breeds difficulty is the legibility of combinatorial explosion. With few verbs, the player can enumerate every available move in their head. Precisely because they can enumerate them, real difficulty rises when all of them look like dead ends. Verb-heavy games leave the escape of 'maybe there's a verb I haven't tried,' but subtractive design has none. The moves are visible, and still it won't solve. That closed tension is the bite unique to subtractive puzzles.

The second reason is affordance and observational resolution. With a small vocabulary, every detail of the board starts to matter: a single wall in Sokoban, one fruit in Snakebird, a single char mark on a sausage. Subtraction does not cut information; it raises the density of what remains. As I wrote in Shaping the Learning Curve, fewer verbs soften the vertical walls of learning and widen the room for players to notice things themselves.

Third, subtraction is a foundation for extension. 2019's Baba Is You set one layer, rewriting the rules, atop Sokoban's minimal set. The verbs are close to push and walk, yet by pushing words on the board to reassemble grammar, infinite mobility emerges. Firm the skeleton by subtraction, then add exactly one moving part. This is the richest development of subtractive design, and proof that verb-minimalism is no mere abstinence.

Closing

From Sokoban to Baba Is You, the lineage of subtractive design is consistent. Narrow the verbs, run that one verb through a deep axis, raise the density of what remains. Snakebird layered the body, Stephen's Sausage Roll rotation, A Monster's Expedition exploration, Bonfire Peaks loss, each atop a minimal set. What they share is designing difficulty by deciding what to keep, not what to add. Subtraction is one of the most reliable grammars thinking puzzles have honed over forty-four years.

If I made a puzzle next, I would start by narrowing to a single verb. Then I would spend a long time deciding which side effect of that verb to put at the center: the snake's body, the sausage's facing, the way a log falls. The difficulty of subtractive design is not the cutting itself but discerning the one point that remains after the cut. I leave the reader a question: if you could keep only one verb, what would it be?