The production checklist for a five-reel slot

Updated 2026-08-24

Use this checklist before integration begins

A handoff identifies each file's role, dimensions, alpha, stacking order and placement. The core package covers reels and stages, plus enabled UI, win, bonus, prop, mascot-pose and front-matter packs. The team supplies product-specific screens. Check the slot art canvas and safe-area specifications.

1. Reel symbols

• Wild: one isolated object on transparency, with a closed silhouette and external light.
• Scatter: a separate isolated object whose open silhouette and internal light remain distinct at 96 pixels.
• High tier: premium themed objects. A normal prompt derives up to four when it contains enough nouns; an explicit brief can request more.
• Low tier: simpler user-named icons or card ranks when fields are blank. They receive no plaques.
• Mascot bust: when it takes a high-tier slot, use the same character's head-and-shoulders view.

Base symbols are alpha-cropped, centred 512×512 PNGs. Fill is 80% for special, 76% for high and 70% for low; prompt margins are 10%, 12% and 14%. Match filename, label, tier, dimension and symbol index to asset-set.json. At 96×96, silhouette, focal detail and Wild/Scatter distinction must survive. See visual symbol tiers.

2. Registered symbol layers

Do not bake these layers into the symbol. Plaques are separately generated and framed to the same 512×512 canvas. The other four are derived from final alpha and disabled by default. The stack is plaque, shadow, glow, outline, symbol, rim. Every layer must share the base PNG's dimensions and origin.

3. Desktop and phone stages

• Landscape background: background.png, normalized to 1920×1080 for the default 16:9 stage.
• Portrait background: background-mobile.png, independently composed at 768×1366 for the 9:16 stage, not cropped from desktop.
• Reel cabinet: one generated 11:7 board with a dark, lightly grained panel and quarter-cell rail, fitted to both stages.
• Title lockup: one transparent 1200×400 asset spelling the exact game name once.
• Corner ornament: one 512×512 top-left asset; the manifest publishes four placements and required flips.
• Stage previews: one composited PNG per orientation for framing and z-order.

Keep the environment continuous behind the reel-safe area, using lower contrast instead of an empty rectangle. The cabinet supplies the panel. Its measured opening is snapped to 5:3 for square cells in a five-by-three grid. Use the manifest opening; do not estimate it from a preview or hard-code another rectangle.

4. Character art

• Mascot column: mascot/<slug>.png at 512×1536, with one full figure, footing and contact shadow.
• Mascot reel identity: a high-tier bust with the same face and head-and-shoulders design.
• Optional portraits: 768×1024 art recorded as portraits, not paytable entries.

The mascot must be a cut-out, not scenery. Its body turns three-quarters toward the board while its head and eyes face the player. Its footing must belong to the submitted world; transparent space under a standing pose makes it float. See the mascot design guide.

5. Controls and state art

Controls are themed hardware on transparency:

• Primary: ui/spin-button.png, round, largest and deepest in relief.
• Secondary: autoplay, turbo, menu and info, distinguished by outer form rather than generated glyphs.
• Surfaces: ui/hud-bar.png for balance, bet and win; ui/value-plate.png for one number; and ui/progress-bar.png as an empty track. Wide plates have ornamented ends, plain centres and measured nine-slice insets in the manifest.
• States: hover, pressed and disabled versions derived from idle art under layers/ui/<name>/ for exact registration.

Ship only controls backed by real actions and states.

The win pack contains increasingly rich win/big-win.png, win/mega-win.png and win/epic-win.png lockups, radial win/burst.png, and win/token.png for the screen shower. The token comes from the submitted world rather than defaulting to a coin. The team still decides whether line wins reuse symbol glow, how many win levels the maths provides, and whether multipliers need digits, a reusable frame or both.

6. Bonus-mode package

• bonus/background.png and bonus/background-mobile.png: the same location under changed light, referenced against the finished base backgrounds.
• bonus/free-spins-banner.png: the spelled entry lockup.
• bonus/counter-plate.png: an empty plate with a high-contrast centre for remaining spins.
• Team-defined retrigger and completion banners, meters or collectors, split only where animation requires it.
• A transition that leaves the cabinet, symbols and reel window in place.

Use light, atmosphere and state hardware for contrast rather than creating an unrelated world.

7. Loading and distribution art

• Loading: loading/splash.png at 1920×1080 and loading/splash-mobile.png at 768×1366, composed from the background, title and mascot. The manifest places the progress track.
• Lobby: marketing/lobby-tile.png at 1200×1200 and marketing/lobby-banner.png at 1920×1080, with title and focal subject inside crop-safe bounds.
• Paytable: empty framed info/paytable-panel.png; the client prints pay values.
• Store crops: only publisher-requested sizes. Do not stretch 16:9 art into a square.
• Package archive: the complete ZIP plus an unpacked copy under source control or asset storage.

These four compositions reuse set assets and add no generation cost. Approve the title, mascot and backgrounds first.

8. Final handoff checks

1. Open every PNG and verify expected alpha.
2. Match filenames, dimensions, roles and placement rectangles to the manifest.
3. Test all tiers at 96 pixels and in a moving five-by-three grid.
4. Switch desktop and phone without reusing desktop coordinates.
5. Confirm registered layers align without independent axis scaling.
6. List every missing product-specific screen or unresolved state.
7. Archive the set before the project card's deletion date.

A handoff is ready when another developer can place every core asset from the manifest and identify all missing product states. If files fail as a family, review the reference and harmonization chain before adding art.