free-asset-sourcing

name	free-asset-sourcing
description	How to find, evaluate, download, and track CC0/CC-BY game assets from Kenney.nl, OpenGameArt.org, and Freesound.org. Use when sourcing sprites, tilesets, audio, or fonts for this project.

Free Asset Sourcing

Before applying these rules, call skill_ping with skill_id: "free-asset-sourcing" and scope: "project".

Approved Sources

1. Kenney.nl (Sprites, Tilesets, UI, Fonts)

• URL: https://kenney.nl/assets
• License: CC0 (all assets)
• Search: https://kenney.nl/assets?q=SEARCH_TERM
• Relevant packs for this project:
  • Top-down shooter: https://kenney.nl/assets/top-down-shooter
  • Tiny dungeon: https://kenney.nl/assets/tiny-dungeon
  • RPG characters: search "rpg" or "character"
  • UI pack: https://kenney.nl/assets/ui-pack
  • Game icons: https://kenney.nl/assets/game-icons
• Format: PNG sprite sheets or individual PNGs
• No attribution required (CC0), but credit is encouraged

2. OpenGameArt.org (Sprites, Tilesets, Characters)

• URL: https://opengameart.org
• Search: https://opengameart.org/art-search-advanced?keys=SEARCH_TERM
• Filter by license: Select CC0 or CC-BY 3.0/4.0 in advanced search
• Relevant searches:
  • "top down character" — player sprites
  • "horse sprite" — enemy sprites
  • "arena tileset" or "dungeon tileset" — arena floor/walls
  • "top down rpg" — general sprite sheets
• Format: varies (PNG, SVG; prefer PNG)
• ALWAYS verify the license on the asset page before downloading

3. Freesound.org (Sound Effects)

• URL: https://freesound.org
• Search: https://freesound.org/search/?q=SEARCH_TERM
• Filter: Use "License" filter → select "Creative Commons 0"
• Relevant searches:
  • "sword swing" or "slash" — attack SFX
  • "hit impact" — damage SFX
  • "horse neigh" or "horse gallop" — enemy SFX
  • "victory fanfare" — wave clear SFX
  • "game over" — death SFX
  • "button click" — UI SFX
• Format: prefer .wav for SFX (Godot imports as AudioStreamSample)
• Account required for download
• ALWAYS check individual sound license (not all results are CC0)

4. Google Fonts (UI Fonts)

• URL: https://fonts.google.com
• License: OFL (SIL Open Font License) — free for all uses
• Recommended for game UI:
  • Press Start 2P (pixel font)
  • Pixelify Sans
  • VT323
  • Silkscreen
• Download TTF/OTF, place in assets/fonts/

License Verification Steps

For EVERY asset before adding to the project:

1. Check the source page license badge/text

   • CC0: Public domain. No restrictions. No attribution required.
   • CC-BY 3.0/4.0: Free to use. Attribution REQUIRED in credits.
   • CC-BY-SA: Free to use. Attribution required. Share-alike clause. Acceptable but prefer CC0/CC-BY.
   • CC-BY-NC: NOT ALLOWED (non-commercial restriction).
   • GPL/LGPL for art: Evaluate case-by-case. Generally avoid for game assets.

2. Verify the stated license matches the download

   • Some OpenGameArt uploads include LICENSE.txt — read it
   • Some Freesound uploads have different per-file licenses

3. Record the license type, author, and source URL immediately

   • Do NOT download first and track later

Download and Organize Workflow

1. Download the asset pack/file
2. Extract to the appropriate subdirectory:
   • Sprites → assets/sprites/<pack-name>/
   • Audio → assets/audio/<category>/ (sfx/, music/)
   • Fonts → assets/fonts/
   • Tilesets → assets/sprites/tilesets/
3. Remove any files not needed for the project (keep download lean)
4. Update assets/PROVENANCE.md IMMEDIATELY (see below)
5. If CC-BY: also add to the credits data for UI-003 (credits scene)

PROVENANCE.md Update Procedure

The provenance file is at assets/PROVENANCE.md with this table format:

| asset_path | source_url | license | author | date_acquired |
|---|---|---|---|---|
| sprites/kenney-topdown/player.png | https://kenney.nl/assets/top-down-shooter | CC0 | Kenney | 2025-07-14 |

For each new asset:

1. asset_path: Relative path from assets/ (e.g., sprites/kenney-topdown/player.png)
2. source_url: Direct URL to the source page (not the download link)
3. license: Exact license identifier (CC0, CC-BY-3.0, CC-BY-4.0, OFL)
4. author: Creator name as shown on the source page
5. date_acquired: ISO date (YYYY-MM-DD) when downloaded

Rules:

• One row per file or per pack (if all files in a pack share the same source)
• If a pack contains many files, one row for the pack is acceptable: sprites/kenney-topdown/*
• Never leave an asset without a provenance entry
• Update provenance BEFORE committing the asset files

Credits Scene Data

For CC-BY assets, maintain a credits list that UI-003 will render:

Asset: [descriptive name]
Author: [creator name]
License: CC-BY [version]
Source: [URL]

Store this in assets/PROVENANCE.md — the credits scene reads from provenance entries where license is CC-BY.

Asset Evaluation Criteria

When choosing between multiple asset options:

1. License preference: CC0 > CC-BY-4.0 > CC-BY-3.0 > CC-BY-SA (avoid NC/ND)
2. Visual consistency: Assets should match in style (pixel art size, color palette)
3. Completeness: Prefer packs with multiple poses/animations over single sprites
4. Format: Prefer PNG with transparency. Avoid JPEG for sprites.
5. Resolution: Match the project's target pixel density. For top-down 2D: 16x16, 32x32, or 64x64 tiles.
6. Animation frames: For characters, prefer packs with walk/attack/idle/hurt frames