RDOMap is a client-side interactive map web application for Red Dead Online, deployed as a static site using vanilla JavaScript and Leaflet. In production it loads dozens of game-curated JSON datasets (camps, plants, shops, bounties, legendary animals, encounters, free-roam events, singleplayer collectibles, interior overlays), converts game-engine coordinates to web map coordinates via hardcoded linear formulas, and renders thousands of categorized markers with clustering, tooltips, heatmaps, and user-generated pins. State persists in localStorage through a generic SettingProxy abstraction, and live data (daily challenges, free-roam event schedules) is fetched from external APIs with Promise.allSettled fallbacks. There is no build step, no framework, and no top-level package manager; index.html loads ~26 global scripts plus vendored Leaflet plugins. Architecturally the code is a collection of global classes per content category (Locations, Shops, Bounties, Plants, etc.) sharing common helpers in loader.js, settings.js, language.js, and map.js. The most genuinely reusable pieces are SettingProxy (typed localStorage proxy with defaults, coercion, and change listeners), the Loader (per-file cache-busting JSON fetcher with consumeJson memory release), and the DOM i18n system (data-text translation with English fallback across 30+ Crowdin-synced locales). The data model is notably consistent: nearly every dataset uses the same {text, x, y, radius?, locations[]} record shape with color keys, which makes the content layer predictable. The codebase is functional and actively maintained (recent commits, daily Crowdin sync via GitHub Actions, 26 open issues), but it shows its age and community-project character: duplicated marker/popup logic across category files, global mutable state (window.nocache), commented-out debug code, vendored dependencies with no upgrade path, and no automated tests. Game-data JSON contains copy/paste artifacts (e.g., wild camp spawns duplicated in camps.json), and translation files show uneven completeness and errors across locales. It is not a reference for modern front-end architecture, but several helper modules and the canonical marker-data schema are worth extracting.