Guide

01 — Getting Started

Open the file. That's it.

Naita is a single HTML file. Open index.html in any modern browser — Chrome, Firefox, Safari, Edge. No installation, no server, no internet connection required after the first load.

On the home screen, choose your role for the session:

• Game Master — access your campaign library, manage entities, run combat, write journals, and prepare packages for players.
• Player — manage your investigator sheet, keep a personal journal, and import packages from your GM.

Your choice is remembered between sessions. Use Switch Mode to change it at any time without losing data.

02 — GM Mode

Campaigns, entities, and the whole picture.

The GM home screen shows your campaign library. Each campaign is an independent save file — a .cths archive containing all entities, journals, combat state, compendium items, and any associated images.

Entities

Entities are the people and creatures in your campaign — investigators, NPCs, Mythos horrors. Each entity has characteristics, skills, inventory, weapons, spells, and an optional portrait image.

• Click + New Entity in the Sheets sidebar to create one.
• All fields save automatically as you type — no save button needed.
• Click any underlined stat or skill label to roll dice for that value.
• Drag entities into folders to organise a large cast.
• Export a single entity as a .ctha file to share it with other GMs.

Compendium

The Items tab holds your campaign's compendium — reusable weapons, spells, and gear. Add an item once; assign it to any entity from their inventory panel. Compendium items travel with the campaign save.

03 — Player Mode

Your investigator. Your notes. Your sheet.

Players access a separate campaign library that holds their own investigator data. GM packages can be imported to pull in entity templates, handout journals, and compendium items the GM has prepared.

• Create a campaign to hold your investigator sheet and personal journal.
• Import a .cthpkg file from your GM to receive shared assets.
• Your data is stored separately from the GM's — the GM cannot see your personal notes.
• Export your investigator as a .ctha file to hand to the GM at the end of a session.

04 — Journals

Rich text. Images. Categories. All in one place.

Journals are the narrative layer of Naita — session notes, handouts, lore entries, and anything else that needs to be written down and potentially shared.

• Click the Journals tab in the sidebar to see your entry list. Click any entry to open it.
• The editor supports bold, italic, underline, strikethrough, headings (H1/H2), and bullet or numbered lists via the formatting toolbar.
• Insert images using the 📷 Image button. You can upload a file or paste a URL.
• Paste or drag-and-drop an image directly into the editor — it is automatically stored in the campaign's resource archive.
• The 🔗 Linked / 💾 Local toggle in the footer controls whether URL images are downloaded and stored locally on the next save, or kept as external links.
• Mark entries as Handout to share them with players via a campaign package.

05 — Combat

Initiative. HP. The round-by-round grind.

Switch to the Combat workspace tab during a scene. Entities loaded in the current session are automatically added to the tracker with their weapons pre-populated as read-only rows.

• Set initiative values and click Sort to order combatants.
• Use the + / − buttons to adjust HP. The bar colour reflects health state.
• Click a combatant's HP value to set it directly.
• Press Next Turn to advance. Dead combatants are dimmed but stay in the list until removed.

06 — Files & Images

Portable archives. Everything in one file.

Campaign save files (.cths) are ZIP archives. Inside, JSON files hold all structured data. A resources/ folder holds binary images, named by their SHA-256 hash to prevent duplication.

• Export your campaign from the sidebar's ⬇ Export Campaign button.
• Images are only included in the export if they are actively referenced by an entity, journal, or compendium item — deleted images are excluded automatically.
• Import a campaign file on any device to continue exactly where you left off.
• Individual entities and journal entries can be exported as standalone .ctha files for sharing.

Images are stored in browser memory (IndexedDB) during a session and packed into the save file on export. They persist across reloads without exporting, but exporting is the only way to move them to another device.