Features
Eldritch OS is not a map tool with a character sheet bolted on. The map editor, your homebrew, the assistant that drafts against them, and the table you play on are one system — which is why they can see each other.
The difference
Mark a region on the map and have it drafted: read-aloud boxed text, the encounter built around the creatures already standing there — by name and CR, with positioning, tactics and triggers — and traps with a DC, damage, and how they are found.
Turn a line of description into an NPC with a portrait, kept in the campaign alongside everything else.
Give an NPC a voice and hold a spoken conversation with them during the session.
It reads your scenes and regions and suggests edits. It cannot write to them: changes arrive as proposals you apply or reject, enforced at the API rather than by instructions in a prompt.
Describe the room you want and have the battle map drawn for you, ready to calibrate and drop tokens onto.
Nothing here writes to your campaign on its own. The assistant drafts; you decide what reaches the table.
An NPC responding as an agent gets a toolset you pick per character. Let the innkeeper read the current scene and the party roster; deny them your region notes. A shopkeeper can read inventory and propose a sale — which still needs your approval.
They can also ask a player for a persuasion, intimidation or deception check before answering.
Making things
Draw rooms, corridors, doors and stairs, fill them with floor and terrain textures, and calibrate the grid — or upload a map you made elsewhere.
Author your own monsters and content in the same compendium as the SRD material, with the same tools, filterable by source.
Keep NPCs and map regions attached to the campaign, so prep is a thing you build rather than a folder of documents.
Assemble encounters and prepared scenes ahead of time, then drop the party into them without rebuilding the board.
SRD 5.2 content ships built in and searchable. Your own entries live beside it, filtered by source so you always know which is which.
At the table
Upload or draw a map, drop in tokens, and snap to the grid. Player and GM views stay in sync as you move.
Reveal the dungeon as the party walks it. Hide and reveal tokens with one click when the ambush springs.
Roll initiative for the whole board, track conditions on each token, and see hit points at a glance.
Read the guideSketch on the map mid-session and measure range before committing to the fireball.
Switch between prepared scenes without breaking the session — the tavern, the road, the boss room.
Physics-based dice everyone at the table can watch land.
Around the table
A guided builder and full interactive sheets for D&D 5e, with SW5E supported as a second ruleset.
Bring an existing character across instead of rebuilding it by hand.
Read the guideOrganise a campaign, its sessions, its party and its loot so prep carries into play.
A documented HTTP API with Swagger docs for anything you want to build yourself.
Ahead of us
These are designed and coming, not available today.
Coming from another tabletop? Compare with Owlbear Rodeo.
Alpha playtest
Eldritch OS is in alpha, and things will break. The ask is to run a session or two on it and tell us what did. We bring tables in a few at a time.