The Alibi: art brief

Status: drafted 2026-10-14 by Claude for Sarah's review. This brief commissions every painted asset for The Alibi's first build. The app already references the resource names in section 7, with placeholders, so art can land without code changes.

The app draws every word: the account, the papers' text, the SAT stem and choices, the replies, the credibility meter and the account sheet's marks. The painter makes the room, one seated suspect, five blank paper props and the Case Board tile.

1. The game the art serves

A suspect sits across a table from the player and gives a six-line account. Each round, one paper from the file lies on the table between them. The player reads it, picks a reading of an SAT-shaped question, and then either presses the reading across the table or lets the line stand. The suspect answers. After six rounds the player files a finding. ([Spec](the-alibi.md), §2 and §5.)

The art therefore needs:

• a room that holds still for the whole case and leaves most of the screen calm for reading;
• a suspect who is present and attentive across the table, with the face out of frame (spec §11, decision 3);
• papers that look like different objects on the table, with blank areas where the app sets the text;
• a small tile for the Desk's client files, beside Prime Suspect.

2. Sources of truth

3. The room

A small interview room in an old municipal building after hours. It is used for one conversation at a time. It is plain, worn and quiet.

Lighting. One pendant lamp: a conical enamel shade in dull cream, hanging low over the table's centre on a plain cord. Its lower rim enters the top of the frame. It lights a warm, soft-edged pool on the table and the suspect's hands, and leaves the walls in cool, falling shadow. A faint cool spill comes through the door's wired glass. Nothing else lights the room.

The pool of light is where the papers sit, so it must be even and matte across the middle of the table: no hot spot, no bloom, no glare on the linoleum.

Mood. Patient and close. Someone is about to explain where they were.

Distinct from the other rooms.

Never in the plate. People, faces, papers, cups or props, text or numerals, a second light fixture, a two-way mirror (it is a cliché and would invite a face in reflection), a window to the outside, wet or glossy surfaces, smoke, bloom, spotlight beams.

4. Camera, composition and layout

Camera. Seated in the player's chair at the near side of the table, eye height about 1.15 m, looking straight across and slightly down. The suspect is seated opposite.

Framing rule. The top of the frame cuts the suspect at the shoulders. The lamp shade's lower rim hangs into the top of the frame on the centre line, in front of where the suspect's face would be, so the frame reads as deliberate: the light is on the hands and the table, and the face is above the light. No part of the chin, mouth or jaw may appear in any layer at any state.

Canvas. Portrait 2:3 at 1536 × 2304 native where the generation tool allows it, as for Kingpin's room. If only 1024 × 1536 is available, generate the set at that size and upscale every registered layer by exactly 1.5× as one set, by one method, and record both sizes in the manifest. An upscaled file is never described as native.

Phone fit (iPhone 16 Pro Max portrait, 440 × 956 pt). The app fills the screen's height with the plate and crops the sides. At that scale a 2:3 plate is 637 pt wide, so about 98 pt is cut from each side, 15.5% of the plate's width per side. Keep the lamp, the suspect and the hands inside the central 66% of the plate's width. The edges may carry wall and door only.

Bands, as a share of plate height:

Layer order. alibi_room, alibi_suspect_shadow, alibi_suspect, the prop layer (if any, section 5.3), then the app's paper prop, account sheet, choices, overlays and UI.

5. The suspect

5.1 The base figure

alibi_suspect is one seated figure, cropped at the shoulders by the frame, in the stacking chair, forearms on the table's far edge, hands folded loosely. They are attentive and still. The register is cooperative on the surface and guarded underneath; the hands are the only performance.

• Finish. People are painted and places are inked, as in Kingpin's Room: soft painted realism, no ink contours, matching Sarah's softened r6 portraits. Matte fabric and skin, the lamp's warm light from above, cool falloff at the shoulders.
• Neutral base. The base wears a plain dark charcoal jacket over a mid-grey shirt with no visible tie, jewellery, watch or insignia, so it reads as nobody in particular. Torso build is medium and does not commit to a gender; the per-case variants do that work through sleeves and hands.
• Hands. Clearly drawn, natural, five fingers each, relaxed. Hands are where generated figures most often fail, so they are an acceptance gate (section 9).
• Registration. Full-canvas transparent PNG at the plate's size, registered to alibi_room, with its own alibi_suspect_shadow (multiply) for the contact shadow on the table and chair.

5.2 Per-case variants

Each case's suspect is the base figure with three things changed: sleeves, hands and one prop. The silhouette and pose stay identical so every variant registers to the same plate and the app can swap them with no jump.

How variants are produced. Each variant is a masked edit of the base, never a fresh generation:

1. The pack keeps masks/alibi_suspect_edit.png: white over the sleeves, cuffs and hands, black elsewhere.
2. The variant is painted inside that mask only (new sleeve fabric and colour, new cuffs, the suspect's own hands: age, skin tone, rings, nails, a bandage, ink stains).
3. Outside the mask, the variant is pixel-identical to the base. The importer checks this (section 8).
4. The prop is a separate transparent layer, alibi_prop_<name>, registered to the plate and placed on the table at the suspect's side, inside the suspect band. One prop per case at most.

Variants are named alibi_suspect_<case_id> with a matching _shadow. Props are named for the object (alibi_prop_tape_measure). The first build ships the base only and uses it for every case. Variants follow each case's casting.

Example: The Spare Key (case 014), Mara Tooley, costume lead. Sleeves of a moss-green cardigan pushed to the forearm, a pincushion cuff on the left wrist, hands with short nails and a thimble callus, a tape measure coiled by her right hand.

5.3 What the suspect never does

No gestures toward the papers, no pointing, no fists, no hands raised. The reply is carried by the app's text and timing (spec §5, step 5), so the figure needs no reaction states in v1. A state change in a later version would be a registered layer swap within the same mask.

6. The papers

Five blank paper props. The app sets every word on them, rotates each a degree or two, and lays one on the table each round. The papers are seen front-on and flat, with no perspective, so text set on them reads as print. Their silhouettes do the work of telling them apart (Dossier v5 §10).

Rules for every paper.

• No lettering of any kind, no numerals, no logos, no handwriting, no stamps. The app sets text, and any painted mark would compete with it.
• No horizontal ruled lines in the text area. The app's line height would never match them. The ledger's vertical margin rule and the statement's empty header box are the only rules.
• Transparent outside the paper, with a soft contact shadow baked into the alpha, like kingpin_paper.
• Nine-slice ready. Keep edge and corner character (clips, perforations, staple, tear) within about 110 px of the border and the middle plain and even. The app stretches a paper vertically to fit its text. Record cap insets in the manifest. The bulldog clip and the staple sit inside their cap.
• Even tone. Text in the house ink must read at the app's body size on every paper, the pink slip included.

7. Asset manifest

The app references these names now, with placeholders. Folder: Image-Assets/The Alibi/the-alibi-production/.

Also in the pack: manifest.json (every file's dimensions, native size, any upscale method, alpha, byte size, SHA-256, and the papers' cap insets, in the same shape as Kingpin's), specs/prompts.json (exact prompts and references for every image), and review/ (contact sheets and the composites of section 9).

Not commissioned in v1: per-case suspect variants and props (they follow each case's casting), reaction states, a title screen, stamps, and a close view of the papers.

7.1 The Case Board tile

alibi_case_folder sits in the Desk's client files under Prime Suspect's tile, at the same size. Prime Suspect's tile is a figure seen from behind on a flat sage-grey ground. The Alibi's tile is a closed manila case folder lying on the grey linoleum of the interview table, lit from above by the lamp's pool, with a single paper corner showing from inside and the bulldog clip on the folder's edge. No lettering and no tab label. At 44 pt it must read as "a file on a table" and must not be confused with Prime Suspect's figure.

8. Import contract (proposed tools/alibi_import.py)

Proposed only; not written. It follows tools/kingpin_import.py.

• Reads Image-Assets/The Alibi/the-alibi-production/ and checks every file against the SHA-256 in manifest.json first, so a retouched or swapped file stops the import.
• Checks each file's dimensions and alpha against the manifest; checks that every alibi_suspect_<case_id> variant matches the base outside masks/alibi_suspect_edit.png; checks that the papers carry no opaque pixels outside their silhouette apart from the baked shadow.
• Writes Peregrine/Assets.xcassets/Alibi/alibi_<name>.imageset (one universal image per set, as Kingpin does), and Peregrine/Assets.xcassets/alibi_case_folder.imageset at the catalog root beside game_prime_suspect.
• Plates are re-encoded as JPEG q86 4:4:4. Figures and props are cropped to their alpha bounds, and a generated Peregrine/Views/Alibi/AlibiCatalog.swift records each crop's position on the full canvas, so the app places them without decoding full-canvas transparent layers. Papers keep PNG, and their cap insets are written into the catalog.
• Never overwrites a master in the pack, and never runs during an art-review task. It runs only in an authorized integration task (ASSET_PRODUCTION, "Before producing assets", step 3).

9. Acceptance

Face rule. At every state and variant, no chin, mouth, jaw or face appears in any layer. The lamp shade's rim and the frame's top edge are the only things above the shoulders.

Hands. Two hands, five fingers each, natural joints, relaxed, at native and phone size. Variants pass the same check.

Registration. alibi_suspect sits in the chair with its shadow aligned; swapping the base for any variant moves nothing outside the edit mask. A prop layer sits on the tabletop at the right scale and perspective.

Reading. Body text and four choices, set by the app in the house ink at its sizes over the table band, read without effort. Every paper, stretched to the tallest likely paper text, keeps its corners, clip, staple and perforations intact, and its text reads without effort, the pink slip included.

Distinctness. Side by side with Kingpin's room and The Wager's table, the three cannot be confused: different table, different light, different palette. The tile cannot be confused with Prime Suspect's at 44 pt.

Phone. Composite at 440 × 956 pt with placeholder UI: the suspect and lamp sit inside the central crop, the reply area beside the suspect is calm, the table band holds a paper, the stem and four choices, and the dock reads over the bottom band.

Style. ART_DIRECTION's visual QA checklist, every item recorded. One lamp only. Matte linoleum. No unrequested additions.

Review composites in review/: the plate alone; plate with the suspect; a round in progress (paper, stem, choices, dock); the account sheet open; each paper stretched short and tall with sample text; the tile at 44 pt beside Prime Suspect's.

10. Generation prompts

In the repo's style (Image-Assets/Kingpins-Room/specs/prompts.json). Record the exact prompt, model, size and references for every image actually used.

Shared style line, appended to every prompt: Matte materials, no gloss. Restrained practical light. No text, numerals, logos or signage. No people unless the prompt asks for a figure.

alibi_room

Interior of a small interview room in an old municipal building at night, seen from a seated position at the near side of a small steel-framed table, eye height about 1.15 m, looking straight across. Graphic-novel noir finish: deliberate ink contours, restrained painterly shading. The table top is worn dark battleship-grey linoleum with a brushed steel edge band, scuffed where elbows rest, one corner slightly lifted; it fills the lower 60% of the canvas, matte and even. Across the table an empty space where a person will sit, with no chair. One pendant lamp with a dull cream conical enamel shade hangs low over the table's centre on a plain cord; its lower rim enters the top of the frame on the centre line at about 6–14% of image height. It casts a warm soft-edged pool on the table; the walls fall off into cool shadow. Walls: teal-grey gloss paint to shoulder height, faded matte cream plaster above. Back wall left of centre: a closed steel door with a wired-glass panel letting in a faint cool spill. A radiator; a wall clock with hands and no numerals. Keep the central 66% of width uncluttered behind where the person will sit, and leave a calm wall area to one side. No chair, no people, no papers, no objects on the table, no second light, no mirror, no window to the outside. Portrait 2:3, 1536 × 2304.

alibi_suspect (generated over the approved plate, then extracted to a transparent layer)

Add one seated person in a plain steel-and-plywood stacking chair on the far side of the table in this exact room, framed so the top edge of the image cuts them at the shoulders: no chin, mouth, jaw or face visible anywhere. The lamp shade's rim hangs in front of where the face would be. Forearms rest on the table's far edge; hands folded loosely, relaxed, five fingers each, clearly drawn, lit warmly by the lamp; cool falloff at the shoulders. Plain dark charcoal jacket over a mid-grey shirt, no tie, no jewellery, no watch, no insignia; medium build that does not commit to a gender. Soft painted realism for the person, no ink outlines, matte fabric and skin, matching the softened painted portrait references (not photorealistic). Keep the figure inside the central 66% of the width, shoulders to hands between 12% and 40% of image height. Change nothing else in the room. Native 1536 × 2304.
References: the approved alibi_room; Peregrine-Grid-Updated/Squares/r6_c02.png and r6_c04.png for the finish only, never the face.

alibi_paper_memo

A single blank sheet of cream letter-weight office paper seen perfectly front-on and flat, with a steel bulldog clip at the top edge and one soft fold line across the upper third. Faint paper tooth, lightly softened corners. No text, no lines, no letterhead, no marks. Transparent background with a soft contact shadow. Plain, even middle for text to be set on it later. 1200 × 1500.
Reference: Image-Assets/Bulldog-Clip.png for the clip.

alibi_paper_log

A blank length of continuous-feed computer printout paper, front-on and flat, with tractor-feed perforated strips and punched holes down both edges and a torn top edge. Very pale green-bar tint bands with no printed lines. No text, no numbers. Transparent background with a soft contact shadow. Plain, even middle. 1200 × 1600.

alibi_paper_slip

A small blank carbon-copy slip in pale oxblood-pink paper, front-on and flat, squarer than a letter sheet, with a perforated tear along the left edge and a faint carbon smudge in one corner. No text, no boxes, no numbers. Transparent background with a soft contact shadow. Even tone suitable for dark text. 1000 × 700.

alibi_paper_ledger

A single blank page torn from a bound account ledger, buff stock, front-on and flat, with a soft gutter shadow and torn binding edge along the left, and one thin vertical red margin rule near the left edge. No horizontal ruling, no text, no numbers. Transparent background with a soft contact shadow. 1200 × 1500.

alibi_paper_statement

A blank witness statement form on off-white stock, front-on and flat, stapled at the top-left corner, with an empty printed rectangular header box near the top and a single blank signature line near the bottom. No lettering anywhere, no ruled text lines. Transparent background with a soft contact shadow. 1200 × 1600.

alibi_case_folder

A closed manila case folder lying on worn dark grey linoleum, seen from above at a slight angle, lit by a warm pool from a lamp above with cool shadow at the edges. A steel bulldog clip on the folder's edge and the corner of a cream paper showing from inside. No tab label, no lettering, no stamps. Graphic-novel noir finish, matte. Square 512 × 512; the folder fills about 70% of the frame, readable at 44 points.

11. Open questions for Sarah

1. Tile name. Case Board and hub tiles use game_<name> (game_prime_suspect, game_kingpin). This brief uses alibi_case_folder because the app already references it. Rename to game_alibi for convention?
2. The suspect's table. Grey linoleum on steel is proposed to keep cream papers legible and to stay far from Kingpin's walnut. A scarred wood top would be warmer but closer to Kingpin and the Desk.
3. Gender-neutral base. The base figure is built to read as nobody in particular, and each case's sleeves and hands carry the person. If the first build plays every case on the base figure, Mara Tooley will look like a man in a charcoal jacket to some players. Commission The Spare Key's variant with the base, or accept the base for the first build?
4. The clock. A wall clock with no numerals adds time pressure to the room. It could also read as a hint that chronology matters. Keep it, or leave the wall bare?
5. Reaction states. v1 has none. A press that lands could later swap in a variant with the hands unfolded. Worth reserving now?

12. Final review

Pros. One plate, one figure and five papers cover every case, so the art cost of a dozen cases a season is per-case sleeves, hands and one prop, each a masked edit that registers by construction. Keeping the face above the frame removes the hardest thing to generate consistently and makes the hands the performance, which suits a game about precise reading. The papers follow the Dossier's object grammar, stay nine-slice and stay text-free, so the app owns legibility. The grey table and single lamp separate the room from Kingpin's and the Wager's at a glance.

Cons. The shoulders-down crop leaves the suspect less expressive than a face would, and replies carry the whole emotional load. A neutral base will read as generic until variants exist. Generated hands fail often, and every variant repaints them. Text-free papers lose some character a printed letterhead would add.

Edge cases. On narrower phones the side crop grows (an iPhone 16 at 393 × 852 pt cuts about 16% per side), which the central-66% rule still covers. A very long paper text stretches a paper into a tall strip, and the slip in particular may look wrong past twice its height, so the app may need to swap the slip for the memo above a length. If the generator cannot keep a variant pixel-identical outside the mask, the importer check blocks it and the variant must be composited by hand. Dynamic Type at the largest sizes pushes the stem and choices into the suspect band, so the table band's 48% is a floor, not a guarantee.

Adjustments worth considering. Commission The Spare Key's variant in the same wave as the base so the first themed case shows a person. Produce one stretched-paper legibility composite before the papers are approved, since the slip's colour is the riskiest choice here.

Confidence: 72 that this brief is the right commission for v1. The lowest-confidence parts are the neutral base figure's read, and whether a generator can hold a masked variant pixel-identical outside the edit area.

Rendered from docs/spec/the-alibi-art-brief.md. The Markdown file is the source of truth.