Features
What Vivarium does
What you get when you sit down to play, grouped by what it fixes. Everything here is built unless it is markedPlanned. Anything marked Subscription comes with the subscription; the rest is part of play on the free plan.
Memory that holds
A long story forgets because a chat is only text. Here, what matters is kept as records you can read.
Kept as records
Facts, scene summaries, memories held by each character, and threads left open are stored as records, not left in text that scrolls away.
A memory inspector
Open it, read what the world remembers, and correct it.
Remember this
One tap on any narrator message keeps it in memory.
A lore book per world
Lore is brought into a scene only when it is relevant, so it never crowds out the story.
Recall by meaning
Connect an embedding model and the application also finds memories close in meaning, not only in wording. The inspector says why each one came up.
Deep, permanent memory
A very long story keeps its memory in play at full depth. On the free plan older memories are kept, and return to play when you subscribe.
Characters with minds of their own
Nobody here exists to agree with you. Characters want things, know things and change.
Characters who can say no
What a character does is decided from their goals, fears and how they feel about you, with dice bounded by their personality. Refusal is a normal result, not an error.
Relationships that run one way
Trust, affection and respect are tracked in each direction. Trust is not always returned.
Knowledge kept apart from truth
Each character speaks only from what they know. They can be wrong, keep a secret, or repeat a lie they believe, and act on all of it.
Characters who age and change
Characters grow older as world time passes, and their personalities develop from what happens to them. Every change records its cause.
Families
Births, family links, and children who grow up over a long story.
Traits you can lock
Lock any trait you never want changed, and it stays as written.
Keep the people you meet
Keep someone the narrator invented as a full character. The AI drafts their card from your scenes, you approve it, and you can leave their hidden depths to be discovered in play.
Pronouns for everyone
Every character has pronouns: she, he, they, or a set you type yourself.
Dice and consequences
Outcomes are decided before a word of prose exists, and what you do stays done.
Honest dice
A check is rolled against your character's skills and conditions before the narrator writes anything. A failure complicates the story instead of ending it.
Moments that are remembered
Insult someone, rescue them, betray them or apologise, and the application records the moment. It moves how they feel about you, and how everyone who saw it feels.
Feelings fade, deeds do not
A flash of fear or anger fades with time. What you did does not. A week of waiting forgives nothing.
Repair that has to be earned
A second apology counts for less than the first, and no repair outweighs the harm it answers.
Promises that bind
A promise you make is kept as an open thread. Keep it or break it, and the person you made it to remembers. If it has a deadline, the deadline can pass.
Standing with factions and places
Acts seen by a faction's members or a place's residents move your standing there, and the cause is written down in words.
Word that travels
People who were not there hear about it later, sometimes exaggerated. News arrives in the digest when you move time forward.
A name you earn
Enough witnessed deeds of one kind earn your character an epithet. Characters who know those deeds use it. Characters who do not, do not.
Two ways back
With a faction that has turned against you, earn your way back through deeds they see, or pay amends to a member. Paying helps once a day, and never past neutral.
You see what changed
A short note under each reply says who will remember what just happened. A character's card lists the causes behind how they feel about you.
Items, locks and needs
Items can change your odds. Doors and chests carry rated locks you can pick. Hunger, fatigue and health rise with time and become conditions.
Fights in words
A fight starts only from a decided act and runs as a tracked exchange of checks. Injuries sit on a named ladder, you can always yield or flee at a known cost, capture comes with a way out, and the cost of losing follows the stakes you chose. Fights can be switched off for any story.
A turn you can take back
Every change is written down with its cause, so a turn can be retracted cleanly. The items, the injuries and the opinions return to where they were.
A world that moves when you move time
The world does not run on a clock of its own. You rest an hour, wait out the night or skip a week, and it catches up.
The scene as it stands
Who is in the room, which door is locked, who is holding the letter. The application tracks places, presence and every item, and hands the narrator the scene before each turn.
Towns, districts and travel
Places connect to other places, and travel between them takes time. Neighbouring districts are a short walk apart.
A calendar with seasons
Each world keeps a calendar, and the clock and the narrator both know what season it is.
Encounters from danger
Travel and waiting roll against how dangerous a place is. Nothing is conjured because a scene went quiet.
Merchants with prices
Merchants hold stock at their own prices, and paying moves real money from your character to theirs.
A world that catches up
Skip an hour or a week and the application works out the interval: who travelled, what changed, and what your character could plausibly have heard.
Characters with lives
Characters keep schedules and walk real routes to follow them. A companion with somewhere to be leaves and comes back.
Factions, events and rumours
Factions pursue their goals, world events happen when they are due, and rumours spread as things people believe, never as things that are automatically true.
Work and wages
Characters hold jobs and are paid for them, and relationships between them shift as time passes.
Worlds to play and to write
One catalogue of worlds written for Vivarium, and the tools to write your own.
Starter worlds
Five starter worlds in different genres, each complete and focused, with a full cast. Open to everyone.
Premium worlds
Larger worlds with the living world in depth, marked Premium. Every one is included in the subscription, and more are added over time.
One catalogue
Browse and search every world in one place, and preview a world before you start a story in it. Each is labelled General or Mature.
Your own worlds
Write places, people, items, lore, factions, routines, events and merchants, then play in them.
Clone a world and change it
Take a private copy of a catalogue world and make it yours. An update to the original never reaches your copy.
Keep the world a story became
Turn a story's world, as it stands, into a world of your own and start a new story from it.
Every story on its own copy
A story runs on its own copy of the world, so editing a world never changes a story under way.
Download what you wrote
The worlds and characters you wrote download as files that carry no secrets, on every plan.
At the table
The play screen, and the work that keeps a long story good to read.
Narration as it is written
Narration streams in. Stop it, regenerate it, or edit a recent turn.
You see where the turn is
While a turn runs, the screen says which stage it has reached: working out what happens, writing, checking.
Your character is yours
The narrator does not speak or act for your character, and you choose the point of view the story is told from.
Fewer tired phrases
The application counts the phrases the narrator overuses and steers it away from them on the next turn.
Refusals named plainly
When your provider declines to write a scene, you are told so. The refusal is never stored as part of the story.
A readiness check for models
Before a model runs a game, a short check shows whether it can, and states the rough cost first. The results build a shared list of models known to work.
Quick start
From a new account to the first scene of a starter world, with a guided walk through connecting your key.
The model named on every turn
Each turn records which model wrote it.
Seven rooms, one bar
Story, You, People, Groups, Belongings, World and History, each one click from the scene, with Help and the menu beside them. The story is the widest thing on the screen and the place to write stays where you need it, on a laptop or a phone.
Quiet by default
One clear action in each place. Help, hints and first-time explanations live behind a question mark, forms open when you ask for them, and nothing empty takes more than one line.
See the odds before you commit
Before you attempt a check, the screen says in words how hard it is. No number, and no roll is spent on looking.
Where you left off
Come back to a story and the screen shows the last scene's summary and the threads still open. Search every closed scene and jump straight to it.
Your look
A light or a dark theme, your text size, a book or a clean story font, and a compact or comfortable layout.
Your account and your model
Bring the AI provider you already use, or let the subscription bring one.
Your own provider key
Bring the AI provider you already pay for and pick the model that narrates each story. Your key is encrypted the moment it is stored and never shown again, to anyone.
The model included
Choose the subscription with the model included and you need no provider account and no key. A monthly allowance comes with a meter you can see, and when it runs out play continues on a lighter model.
See what a story spends
Token usage is recorded for every model call, so you can see what a story costs on your own key.
Sign-in you control
Sign in with email and a password, or with Google or Microsoft. Turn on two-factor sign-in, and sign out any device from a list.
Bring your character cards
Convert a character card or lore book from the tools you use today. You review every value before anything is saved.
Restore what you downloaded
Bring a world or character you downloaded back into your own account, and take any character you wrote out as a card.
Delete your account
Deletion erases your data, with a grace period in case you change your mind.
On the way before launch
Planned for the first release, in the order the roadmap lists them. None of it is built yet.
Personality that matters
Traits from a list each world writes, in opposite pairs, and each one really changes what a character chooses. Relationships described in words that come from the numbers.
How people treat each other
Witnesses remember what characters do to one another, not only what you do. People are judged by the company they keep, and the dead are mourned.
Asking, and owing
Ask someone to hand something over, come with you, keep quiet or tell you what they know, and a yes really does it. Anyone can refuse. Favours and debts are remembered by name.
Money the world keeps
Every coin and item held by the application, trade you can take back, and merchants whose terms follow your standing.
A family that outlives you
Partners, houses with a reputation, children shaped by who raised them, and an heir to carry on when your character dies.
Leading an organisation
Ranks and offices you earn, a succession when a leader falls, and organisations allied or at odds with each other.
Events that never run out
When the written events are spent, the AI drafts new ones within what the world and its current era allow. The application decides which happen.
Places that produce
Fields, mines and rivers that yield, recipes that turn goods into other goods, and stock that restocks as time passes.
Property, careers and debts
Rent or own a place, climb a career, work shifts, hire workers, and pay debts on a schedule with a grace period.
Travel and building
Mounts, vehicles and ships that change how you cross a world, and buildings you raise on land you hold.
Where to go next
The FAQ covers what is free, what the subscription adds and what happens to the things you make. The roadmap shows which phase built each of these, and what is being built now.