Understory

Intro
Garden

Inspiration

The hackathon brief wanted games that build community and keep people coming back. We kept thinking about shared gardens and city farms: places where nobody's individual plot matters as much as the collective thing that gets built over time. Reddit communities already work this way; we wanted the game mechanic to mirror it directly.

What it does

Understory is one shared 10x10 garden per subreddit — not a personal instance. Claim a plot, plant one of six wild species, and it grows in real wall-clock time over a few hours. Water a neighbor's plant to speed it along, which is the core social loop. The real hook is cross-pollination: harvest a plant growing next to a different species and you might discover one of 15 possible hybrids nobody has grown before. The first player to discover each hybrid names it — permanently — in a codex the entire subreddit shares.

How we built it

React inside Devvit Web. All the flora is procedural SVG — petal count, bloom radius, and color are all derived from the species definition and current growth percentage, so there are no downloaded image assets. Redis holds the shared plot grid, the discovery codex, and each player's seed inventory. Cross-pollination checks a harvested plot's four neighbors for a different, sufficiently-grown species and rolls a hybrid from a fixed 15-entry table.

Challenges we ran into

Balancing the growth-timer economy was tricky — too fast and there's no reason to leave the app; too slow and it feels unresponsive. We landed on a 3 hour base grow time that watering can meaningfully cut down.

Accomplishments that we're proud of

A garden that's genuinely shared state, not a personal garden multiplied by users — every plot, hybrid, and codex name is visible and meaningful to the whole subreddit.

What we learned

Permanent naming rights are a surprisingly strong incentive — much stronger than points would have been for the same discovery mechanic.

What's next for Understory

Seasonal resets that keep the six base species but rotate in new hybrid recipes, and a family-tree view of which hybrids came from which base species.