Zero-Screen Dungeon Master: The Voice-Only RPG Where Your Real Walk Drives the Story

This is a submission for the DEV Hacktoberfest Open-Source AI Challenge: Week 1 - Touch Grass.

🌿 What I Built
Most fitness apps and location games scream for your visual attention. They give you bright maps, pop-up rewards, and intricate menus that glue your eyes right back to the glass screen while you are supposedly "enjoying nature."

I wanted the exact opposite. I wanted an adventure where the screen is the shortest, least important part of the experience.

Meet Zero-Screen Dungeon Master (ZSDM): a voice-narrated, pocket-first audio RPG where your real-world physical footsteps drive the story forward.

Here is how a walk works:

Choose an Adventure (or forge a custom one locally using open-weight Gemma AI).
Put on your headphones, tap Start, and slide your phone into your pocket.
Walk forward. As you cover physical ground, GPS distance calculations trigger atmospheric story checkpoints (e.g. every ~80 meters).
Blind Tactical Decisions: When you reach a fork in the narrative, the narrator describes two paths and your phone vibrates in your pocket. Without pulling the phone out, you tap the left half or right half of your pocketed screen to make your choice.
Touch Grass Score: When your walk is finished, the app reveals your expedition metrics—measuring exactly how many minutes your screen was off vs. on, rewarding you with a "Touch Grass Score" (aiming for >90% screen-off time!).
🚀 Live Demo & Code
🌐 Live Web Application (PWA): https://vidishagupta.github.io/zero-screen-dungeon-master/
💻 Open-Source GitHub Repository: https://github.com/vidishagupta/zero-screen-dungeon-master
Video Demo: https://youtu.be/JrDVzizeZKI?si=B0bG5MJPdZwKPc6o

🛠️ How I Built It
The project is structured into two core open-source components:

├── /web # Mobile-first React + Vite PWA (Offline-ready via Service Worker)
├── /forge # Local Open-Source AI Generator (Gemma via Ollama + Zod schema validation)
└── /stories # Gemma-generated interactive branching JSON adventures

1. Zero-Screen Audio UI & Offline PWA (/web) Web Speech API (speechSynthesis): Delivers offline voice narration with pitch, rate, and device voice controls. Zero cloud latency, zero external speech API bills. Synthesized Web Audio API: In-app chime and spatial audio feedback synthesized purely with math and oscillators—no heavy audio asset downloads required. Adaptive Geolocation Tracking: Uses navigator.geolocation.watchPosition with Haversine distance accumulation, GPS noise filtering, and speed sanity checks (dropping jitter jumps >6 m/s or accuracy >35m). It works anywhere on Earth with no fixed predefined map coordinates. Pocket Mode & Wake Lock: Uses the Screen Wake Lock API to prevent mobile browsers from suspending background audio during walks, coupled with an ultra-low-power OLED black pocket overlay. Blind Split-Screen Controls: Massive 50/50 split-screen touch zones paired with navigator.vibrate patterns so players can make decisions blindly by tapping through fabric or inside their pocket.
2. Story Forge: Open-Source AI at the Core (/forge) To create endless, non-linear adventures, I built Story Forge using Gemma (Google's lightweight, high-performance open-weight model) running locally via Ollama.

Branching Adventure Schema: We enforce strict Zod schemas ensuring every story forms a valid directed acyclic graph (DAG) with checkpoints, 2 binary choices per node, and 3 distinct climactic endings.
Automated Repair Loop: If local model output has malformed JSON or broken graph references, the forge automatically feeds the specific validation error back into Gemma for zero-intervention self-correction.
Offline Bundling: The deployed PWA comes pre-bundled with 3 Gemma adventures (The Whispering Canopy, Signal in the Rain, The Forgotten Campus Bell) and includes a JSON importer so anyone can load community-forged stories with zero internet connection on remote trails.
// Validating local Gemma story structure with Zod
export const StorySchema = z.object({
id: z.string(),
title: z.string().min(3),
theme: z.string(),
vibe: z.string(),
checkpointDistanceMeters: z.number().default(80),
intro: z.object({ text: z.string(), nextCheckpointId: z.string() }),
checkpoints: z.array(CheckpointSchema).min(3),
endings: z.array(EndingSchema).min(2)
});
🌲 The Real Outdoor Field Test
Where I Walked: [e.g., Local Community Park Trail / University Quadrangle / Neighborhood Greenbelt]

Weather & Vibe: [e.g., Crisp autumn morning, slight fog, 14°C]

What Happened: [e.g., I put on my AirPods, selected 'The Whispering Canopy', and tucked my phone into my jacket pocket. Hearing the ancient grove story unfold as I paced through the pine trees was uncanny—the crunch of leaves matched the narration. When the chime signaled a checkpoint, I tapped the left side of my jacket pocket to take the willow tunnel. Finished a 580-meter walk in 9 minutes with a 94% Touch Grass Score!]

Photo from the Trail:

💡 Why Does Open Innovation & Open-Weight AI Matter?
This project highlights why open-weight, locally runnable AI is fundamentally transformative:

1.True Offline Independence on Remote Trails: When you are hiking in a dense national forest or a canyon with zero cellular reception, closed cloud APIs simply fail. Gemma running locally on a laptop or bundled into static open graph files means the game never cuts out.
2.Zero Surveillance & Absolute Privacy: Location data and GPS tracks are among the most sensitive personal data points. Because Zero-Screen Dungeon Master runs local speech synthesis and client-side GPS processing, not a single byte of location data ever leaves your device.
3.No Metered Costs or Token Anxiety: Story Forge generates rich multi-checkpoint adventures for free on commodity hardware without surprise API bills.
4.Community Moddability & Fine-Tuning: Anyone can clone the repository, fork the forge prompts, fine-tune a Gemma model for localized folklore, and share adventure JSONs with the open-source community.
🏆 Prize Categories
Google Gemma: Story Forge is designed from the ground up to utilize open-weight Gemma models (gemma2:2b) running locally via Ollama with structured JSON schema repair.
Render Deployment: Frontend PWA statically deployed and served worldwide via Render's free tier.
Project created and open-sourced during the Hacktoberfest 2026 "Touch Grass" challenge window (October 2026).
This is a submission for the Hacktoberfest Open-Source AI Challenge Week 1: Touch Grass
(https://dev.to/challenges/hacktoberfest-week1-2026-10-05)

Comments

[Ananya Gupta]

Very nice 👍