# Stacksmith — game design specification

## Pillars

1. **The bag is the build.** Progression changes the pieces a player must actually place, not a hidden damage spreadsheet.
2. **Randomness is disclosed.** Relative weights, percentages, previews, and incoming curses are readable before commitment.
3. **Wonky means expressive.** Every mutation solves a recognizable stack problem and introduces a recognizable new risk.
4. **Teamwork owns consequences.** Relay partners alternate pieces and share the board, money, and combo. Hold is a team upgrade rather than a starting safety valve.

## Fight loop

1. Draw from the run's weighted bag and preview the next three pieces.
2. Move, rotate, hard-drop, and lock the active piece using familiar battle controls.
3. Convert full rows into sent blocks; each block removes one enemy health and earns $1.
4. Continue clearing on consecutive placements to grow a combo.
5. Read the cursecaster's timer and next named incantation.
6. Adapt to temporary shape, gravity, rotation, and preview curses without leaving the player's board.
7. Survive curses to build a small encounter bonus.
8. Top out and lose, or reduce enemy health to zero, collect the encounter payout, and draft a reward.

## Attack table

| Clear | Sent blocks | Health damage | Base income |
| --- | ---: | ---: | ---: |
| Single | 4 | 4 | $4 |
| Double | 10 | 10 | $10 |
| Triple | 18 | 18 | $18 |
| Four lines | 30 | 30 | $30 |
| Five lines | 45 | 45 | $45 |

Each combo step after the first adds 2 sent blocks. A clear made with a non-base shape adds 3 sent blocks. Every sent block is simultaneously one health damage and $1 of fight income, making one number easy to read. Curses survived add $5 each at victory; the payout screen itemizes both sources.

## Bag rules

- A fresh run has the seven standard tetrominoes at weight 1.0.
- Each draw is independent in the first proof; the probability of a shape is its weight divided by total active weight.
- A drafted mutation normally enters at weight 0.45.
- A tune reward changes one or more relative weights by a disclosed percentage.
- A shape cannot fall below weight 0.05 unless retired.
- Retirement removes a shape and costs money at a repair forge.
- Three-piece preview remains available from the start.
- Hold is absent from the starting kit. A $90 Hold Socket unlocks one hold per placed piece for the team.

The independent weighted model is deliberately more volatile than a seven-bag. If tests show the game becomes tactically unreadable, test a weighted reservoir before adding invisible drought protection.

## Relay duo

- Both players build on one 12 × 22 stack.
- Ownership alternates after every locked piece, including a top-out placement.
- Queue, bag, enemy health, curse state, money, and combo are shared.
- If the team later buys Hold Socket, the unlocked hold is shared; separate personal holds remain an unproven upgrade variant.
- The active player is labeled in the HUD and their blocks receive a subtle ownership pip.
- A team combo rewards consecutive clearing placements even when ownership changes.

This mode tests communication cheaply. It does not settle the long-term question of whether online co-op should use a shared board, paired boards, or both.

## Reward verbs

- **Add:** gain a mutation at a low initial weight.
- **Boost:** increase one shape's relative weight.
- **Suppress:** reduce a troublesome family without removing it.
- **Retire:** pay to delete a shape from the run bag.
- **Relic:** change a rule, such as storing two holds or turning the first single each fight into a shield.
- **Augment:** spend fight money on one shape family, such as Line Dividend making I-beam sends pay +$1 per block.

Post-fight drafts must show three different verbs whenever possible. Three shape additions are not three strategically different choices.

## Cursecaster grammar

Every enemy is composed from three disclosed properties:

- incantation interval;
- small deck of named curse effects;
- reaction to the player's clear type, combo, or bag composition.

The first cursecasters are Scrap Oracle (crooked draws), Gap Witch (preview fog), Gravity Monk (speed pressure), and Mirrorhand (rotation theft). The Kiln boss changes its curse deck and cadence each phase.

## Meta progression

Boss blueprints unlock new shapes, relics, cursecasters, and route events for future runs. They do not raise starting health, base damage, money gain, or starting bag quality. Knowledge and possibility are the permanent progression.

## Accessibility contract

- Shapes are identified by silhouette and label, never color alone.
- Enemy curses always have text, icon, timer, and duration.
- Controls are remappable; if Hold Socket is purchased, hard drop and hold cannot be bound accidentally to the same input.
- Screen shake, flashes, ghost opacity, grid contrast, and motion can be adjusted.
- Pause is immediate in solo and negotiated in multiplayer.