Characters, places, cultures, histories, relationships, quests and ideas become one connected world you can see, understand, test and share.
Stored locally in readable files that remain yours.
Mimir's public beta opens soon.
Worldbuilding software should be easier to understand by watching it than by reading a feature list. Follow one connected world through entries, relationships, trees, timeline, map, story planning, quest simulation, campaigns and Mimir AI.
A 90-second walkthrough of Mimir with the Nine Realms demo world: library, entries, family tree, map, timeline, story planning, a quest test, campaign permissions, Ask Mimir and history. Captions are included.
Pages are useful, but a world is made from the relationships between them. Mimir connects characters, places, cultures, factions, events and stories so you can move from a detail to the wider world around it.
See the same canon through trees, timelines, maps, backlinks and relationships. Build worlds, not documents.
Mimir is not there to make up your canon for you. It retrieves relevant lore, answers from material you have actually written and should make uncertainty visible rather than filling gaps with confident invention. Think of it as lore management that reads before it speaks.
Explore Mimir AIQuestion: Who killed King Aldric?
Mimir: There is no confirmed killer in your current canon. Three entries implicate House Vael, but none state that they carried out the assassination.
This example explains the intended behaviour. It is not presented as a product screenshot.
On Worldsmith and above, Mimir AI reads your prose against your structured details and against connected entries, then shows you each contradiction with its evidence: a date in the text that disagrees with a birth year, two factions describing their alliance differently, a city said to fall that its own entry says never did.
Broken links and duplicate names are caught for free on every plan by Mimir's own checks, with no AI involved.
Simulation, part of Core, lets you step through any quest or dialogue, choose at each branch and watch the world state change, so broken branches surface before your players find them.
Proving Grounds goes further: play your world before it becomes canon, with Mimir AI as the referee reading the Rule entries you have written, rolling dice you can see and playing the seats you leave empty. Proving Grounds is a Loremaster feature.
The captures below show Simulation in Mimir.
Explore Proving Grounds
You don't have to abandon five years of worldbuilding to move to Mimir. Import spreadsheets and documents, or move a whole Obsidian vault, Notion export or World Anvil world. Review what Mimir found before any entry is created, then carry on in a local Mimir world.
Migration remains part of Core because keeping your work is not a premium privilege.
Game Masters can host a Campaign from Apprentice up, and players and Co-GMs join free on Core. Writers can work on one world together in a Writers' Room, where every writer has their own Worldsmith plan and the owner decides what becomes canon. Permissions decide what each person can see and change.
Mimir is not a public social network or a place to meet strangers. It is built for work with the collaborators, friends and players you already know.
These captures show a Campaign in Mimir.
One connected world can move between writing, play, design and production as your project changes.
Build campaigns, hide spoilers, connect factions and histories, test quests and sessions, then host the world for your players. Whether you run D&D, another tabletop RPG or a homebrew system, Mimir gives you campaign management tools that understand the world behind the session.
Track chronology, families, cultures, canon and narrative arcs while keeping the source files under your control.
Keep world and narrative data structured, test state and dialogue logic, and maintain one canonical source of truth.
Your core world lives locally in readable files. You can use the local foundation offline. Cancelling or downgrading does not erase the world you created or lock you out of your own files.
Network functionality such as Mimir AI, hosted collaboration and hosted worlds necessarily transmits the selected data needed to provide that feature. Production subprocessors and retention details will be published once verified.
Every tier includes unlimited local worlds and entries and the full local toolset. Paid plans add monthly Mimir AI credits, desktop and phone sync, hosting and collaboration.
These are the V1 prices. Paid checkout opens with the public beta.
Build your world
Develop your world
or £69.99/year
Bring your world to life
or £149.99/year
Work at professional scale
or £249.99/year
Mimir AI credits. Every account starts with 200 welcome credits, once. Paid plans add a monthly allowance that resets each month. Need more? Credit bundles cost £4.99 for 500, £12.99 for 1,500 and £29.99 for 4,000, and bought credits never expire.
Founders. Every account created in the first six months of the public beta, paying or not, keeps these for life: a Founder badge, 25% extra credits on every bundle, 5% extra monthly credits on any paid plan, and 10% off Shieldwall content packs and collections. Plan prices are never discounted.
Allowances are planning figures and may change before paid checkout opens.
Your own files are not a metered cloud resource.
Moving in and taking your own work out stay accessible.
The GM's plan covers the table. Players and Co-GMs do not need a subscription of their own.
Premium operations may pause, but local content is not erased.
Export to Unreal, Unity and Godot as files is on Worldsmith. Live engine connections and MCP connections for AI tools are later roadmap items, not V1 promises.
See the roadmapBe among the first worldbuilders to use Mimir, help Shieldwall find friction before public launch and receive launch updates.
If the form is blocked by a browser extension, email alexander.goldsmith@shieldwallgames.co.uk.