Inspiration
Reddit is already where people argue about mysteries in the comments. We wanted a daily game that uses that instinct instead of fighting it: a short case file in the post, six theories, and a subreddit that slowly opens extra pages together. Think Clue, but the board is the community and the discussion stays on Reddit.
What it does
The Daily Dossier is a cooperative daily mystery inside a Reddit interactive post.
Each Pacific-time day, everyone in a subreddit gets the same case: five suspects, five locations, five objects. You stamp a theory. The server tells you which categories are right or wrong, but it never sends the answer until you solve it or the day ends.
You get six guesses per day. Wrong theories from logged-in players fill a shared investigation meter. At set milestones, another prewritten clue unlocks for everybody. Personal streaks are saved. Comments stay on the post for talking it out.
How we built it
We built it as a Devvit Web app on the official React template: React + Vite on the client, Hono on the server, Redis for state.
Game logic lives on the server. The client only calls /api/ routes. Daily puzzles are picked from a 32-case catalog with epochDay % catalogLength in America/Los_Angeles, so a whole installation sees the same file. Redis keys are namespaced by date and player. Attempt limits and community hint unlocks use Redis transactions. Devvit Journeys fire on Play, guess, hint unlock, and complete, without personal text in the events.
Challenges we ran into
The local project looked “initialized,” but playtest refused until the app existed on Reddit (devvit upload, not devvit init --force). Journeys also drop events until an app is allowlisted, so the game had to work even when telemetry is ignored. We kept answers off the client, handled Redis write failures as read-only instead of crashing, and designed for a tall mobile post instead of a desktop website.
Accomplishments that we're proud of
A complete daily loop that is understandable in a few seconds: open the folder, pick three things, stamp, see marks, watch the subreddit meter move. Original cases with verifiable solutions. A case-file look that isn’t generic Reddit orange. Rules that fit on the inline splash without a wall of text.
What we learned
Devvit Web is a real client/server app, not a static site: Redis, devvit.json permissions, and playtest-on-Reddit are the actual runtime. Upload creates a private listing; publish is a separate, later step. The hackathon wants games that feel native to comments and community progress, not ports of a generic web game.
What's next for Daily Dossier
Playtest on a real subreddit, tighten difficulty from live guesses, and add more cases. After the hackathon we may add yesterday’s closed-file recap in the feed and, if we launch, keep publishing private until the app is actually ready for a broad audience.
