hidden door

A one-sentence summary

Hidden Door is an online story game that combines role-playing, fan creation, card collection, and procedural storytelling; players create characters and make real choices, and the system generates a constantly evolving adventure based on the rules of the world, the status of the characters, and the plot developments.

Tool Introduction

Hidden Door is operated by Hidden Door, Inc., a company founded in 2020. Its team consists of game developers, narrative designers, artists, and machine learning researchers; Hilary Mason is one of the co-founders and leaders of the company. The products are aimed at readers, role-playing players, writers, world builders, and professional creators who possess original intellectual property.

It is not an unlimited chatbot, nor does it simply continue writing text based on given prompts. The system uses a structured game engine to store characters, locations, items, relationships, and statuses; it then combines manually written plot points, narrative patterns, world rules, and the player’s choices to create a story that can be continued playing.

Current product composition

Main functions

Interactive stories driven by selection

Players confront conflicts, relationships, and goals from the perspective of their characters, describing their actions in natural language. The system determines the outcome based on the current scenario and the state of the world; difficult actions may require the use of specific attributes or dice-rolling mechanisms, so not all actions will succeed without any conditions.

Continuous world state

The game engine stores characters, items, locations, relationships, conditions, and events that have already taken place, so that the subsequent storyline can build upon those earlier developments. Persistent states help to avoid the need to reset the background settings in each turn, but logical inconsistencies can still occur in longer stories, requiring players to correct them manually.

Combination of human narration and machine learning

The narrative team first develops combinable plot elements, genre patterns, character archetypes, and world rules; machine learning then uses the player’s inputs to make selections and reorganizations. Large language models are responsible for specific tasks, such as combining modifier patterns or identifying the visual elements of characters.

Stories and the World

The world is a space that can be explored repeatedly, containing settings, rules, characters, and locations; a story represents an adventure that unfolds within this world. A single scene typically lasts around five to eight minutes, and one story consists of one to three such scenes. Players can embark on more stories within the same world.

Characters, locations, and item cards

During the game, players collect cards representing characters, locations, and items, and choose the elements to incorporate into the next part of the story. Creators can define the background, function, method of unlocking each card, and its relationship to the overall storyline.

Modifier modifier

Each world can provide unlockable modifiers that allow a certain type of element, atmosphere, or narrative pattern to be introduced into another world. This approach is useful for creating contrasts and offering variations for repeated play, but the resulting combinations are still subject to restrictions related to the content level, the rules of the world, and platform security measures.

Private messaging between characters

Players can access private side conversations with the characters through the main storyline, in order to explore their relationships, motivations, and gain additional information. Free users can do this once a day, while the Fan and Creator plans allow unlimited conversations with the characters.

Custom characters and cards

Players can create their own characters, items, and locations; the paid plans also allow for the creation of cards with custom prompts to drive the story forward. The content created must still comply with rules regarding copyright, real persons, minors, and harmful content.

Official and Community Worlds

The catalog includes both worlds created by the Hidden Door team and those published by community creators, and it allows for filtering by type, level of maturity, as well as official or community tags. The worlds currently available fall into categories such as fantasy, science fiction, horror, mystery, romance, comedy, action, and drama.

Highlights of the story and social sharing

Players can share their favorite story snippets, collection results, and world experiences, allowing their friends to continue exploring the same world. Public sharing does not change ownership of the underlying world, characters, or licensed works.

Atlas World Building Tool

Atlas is Hidden Door’s studio for creating playable worlds; the Creator tool allows users to create, test, publish publicly, or share worlds in a non-public manner. It is intended for authors who already have a concept developed, as well as for new creators who only have a few ideas.

Start with the existing writing.

Creators can paste their own story excerpts, world setting documents, character notes, or other writing material as a starting point. After extracting the metadata, the system does not retain the original text that was pasted, nor is it used to train models; however, the world-related content generated thereafter is saved in accordance with the account and product rules.

Start with the Creative Guide.

Users can enter a few key ideas, after which they can use a wizard to choose the story’s hook, genre, tone, physical rules, initial knowledge, thematic pillars, and character archetypes. The wizard helps to develop the structure of the world step by step, making it suitable for those who do not have a complete setting document.

Starting from a blank world

Creators who are familiar with world-building can directly specify the world’s perspective, descriptions, characters, locations, and rules, without having to go through guided questions. This offers greater freedom, but it also relies on the creators themselves to ensure that the structure is coherent and that copyright issues are properly addressed.

Design of characters, locations, and objects

Character cards describe personality, goals, relationships, background, and their role in the storyline; location cards are responsible for setting the atmosphere, providing historical context, and showing how different elements are connected; item cards indicate an object’s capabilities and its use within the story. Good cards are not only collectibles but also capable of influencing the player’s choices and the direction of the story.

Publication and Visibility

After it is released, the world can be added to a public catalog or kept private, accessible only to those who have received a specific invitation. Creators can also test it on their own, share it with friends, or make it available to all players.

Tutorial for Creating the World

1. First, make sure that all the stories, characters, images, and settings you intend to use are either owned by you or for which you have obtained permission for adaptation.
2. Choose to start from an existing piece of writing, a creative guide, or a blank page; do not upload complete works for which you do not have the rights to use.
3. Clarify the world’s core concepts, types, tone, physical rules, player roles, and unchangeable boundaries.
4. Create key characters, and describe for each one their goals, conflicts, relationships, background, and role in the story.
5. Add locations and items so that they can influence choices, rather than merely providing static descriptions.
6. Design opening hooks, plot beats, card unlocks, modifiers, and content warnings.
7. Test repeatedly with different roles and extreme inputs to check for logic, pacing, out-of-bound content, and repeated responses.
8. Decide whether to make the world list public or not, and prepare the creator’s name, biography, and display materials.
9. After release, check player participation and feedback, correct errors, and keep local backups of the important versions.

Guide to playing

1. After registering an account, first select the type, content level, and official or community tag from the world catalog.
2. Read the world description and content warnings, then create a player character suitable for that setting.
3. Once inside the story, describe the choices using concise actions and intentions; add dialogue tone if necessary.
4. When facing difficulties in taking action, accept the attributes or dice roll results; do not treat the system as an unconditional executor.
5. In the desktop card view, manage characters, locations, items, and unlocked modifiers.
6. To gain an in-depth understanding of character relationships, you need to engage in private messages with those characters; users with free accounts should be aware of the daily limit on such messages.
7. After each story ends, continue in the same world, try new card combinations, or share the best moments.
8. If you come across copyright issues, harassment, content involving minors, or other violations, stop sharing it and use the reporting channels.

Which users are it suitable for

• Players of interactive fiction and text-based RPGs: those who want their choices to truly change the state of the characters and the world.
• Tabletop game hosts and long-term DMs: Transform the world setting, NPCs, and narrative elements into an experience that can be enjoyed on one’s own.
• Fan creators: Attempt to create interactive stories on the basis of having authorization or complying with legal requirements.
• Novelists and world builders: Turning existing concepts into playable elements that can be tested and shared.
• Role relationship enthusiasts: Explore friendship, romance, politics, and conflict through the main storyline and private messages.
• Professional creators and IP rights holders: work together with teams to create officially authorized fan experiences.
• Community creators: Publish original worlds and earn potential income based on player participation.

Scenarios that are not suitable

• It is necessary to have a fully defined, sentence-by-sentence controllable layout for traditional novels, as well as to write the final version of them.
• It is hoped that the model will not execute any requests related to adult content, violence, illegal activities, or real persons, under any circumstances.
• Those who intend to make commercial adaptations of copyrighted characters and worlds without having obtained authorization.
• Development teams that require offline, self-hosted models locally or access to the full source code for review.
• Users who treat AI characters as therapists, companions, or sources of professional advice in the real world.
• It is required that all generated text be completely accurate, original, and free of bias or repetition.
• Children under 13, as well as users aged 13 to 17 without the consent of a guardian.

Prices and packages

Hidden Door operates on a free-to-play model with two subscription tiers; no charges are applied per story round. The pricing as of August 23, 2026, is shown below – taxes may apply separately, and any price changes will affect subsequent renewal periods.

Limits of the free version

Free accounts allow unlimited creation of stories and rounds; no charges are applied per round during the story. However, only 5 worlds can be played within the catalog, and there is only one chance per day to send private messages to characters. Mature content and the ability to create new worlds are not included in the free features.

Savings from annual payment

For Fan, the total cost for a year with monthly payments is 95.88 dollars, while paying annually costs 79.99 dollars, representing a savings of around 17%. For Creator, the total cost for a year with monthly payments is 239.88 dollars, whereas annual payment amounts to 199 dollars, again resulting in a savings of about 17%. Annual payment involves paying the full amount for the whole year at once.

Auto-renewal, cancellation, and refunds

Both monthly and annual subscriptions are automatically renewed at the original interval, unless the user cancels them before the renewal date. Cancellation takes effect at the end of the current billing cycle, and the paid services continue to be available during that period; the subscription fee is generally not refundable, except in cases required by law or as permitted by the platform’s discretion.

Content that was canceled

After cancellation, the stories, progress, and custom cards that have been created remain in the account, but the permission to create them on a paid basis is no longer available; access to them can be restored only by subscribing again. Content that has been shared publicly remains subject to the licenses granted previously.

Division of creators

Creators who are 18 years of age or older can release their own worlds through the Creator program or partnership schemes, and they receive a share of the revenue generated by players in those worlds. Under the Fan scheme, 30% of the subscription fees go directly to the creators, but the amount each creator receives depends on factors such as attribution rules, program guidelines, refunds, and adjustments for fraud.

Copyright and content ownership

Player content

Users retain ownership of the stories, suggestions, text, images, and other materials they submit, while granting the platform a non-exclusive, worldwide, royalty-free license necessary for operating, maintaining, improving, and promoting the service. Users must ensure that they have the right to submit and authorize such materials.

The Creator’s World

The creator retains the rights to the world, the text structure, metadata, character descriptions, narrative elements, and other original materials. After publication, the platform can host, display, make technical modifications to, and promote the world; even if the publication is removed, the stories and variations shared by players may still exist.

Risks associated with original works and fan creations

If creators use characters, concepts, trademarks, or other works that do not belong to them, they must have a valid license, access to those elements through the public domain, or some other legal basis for doing so. The review carried out by platform editors does not constitute a copyright license, nor does it guarantee that the works will not be subject to complaints from rights holders or removed from the platform.

Officially licensed IP

Some of the worlds included in the official catalog were created in collaboration between teams and authors or rights holders; these individuals read the works and manually prepared editing guidelines suitable for an interactive experience. The system does not use the books or scripts produced by these collaborators as material for training large language models.

Share content

Players can share highlights from their stories, but such sharing does not grant ownership of the underlying world, characters, creators’ works, or third-party licensed IP. Content created through interaction with other people’s worlds is generally intended for personal, non-commercial use, unless explicit permission is given.

AI, Training, and Art Policies

The story of Hidden Door was not created through a single end-to-end modeling process; it was developed using a game engine, traditional machine learning techniques, a small number of large language model tasks, as well as manually created narrative elements. The character portraits and visual elements representing locations are based on modular materials drawn by the team’s artists, and users can also upload their own artwork if they have the permission to do so.

It’s not that user-generated content is not used at all to improve the system.

Not licensing the foundational models trained on user content to third parties does not mean that such content is never used for internal improvements. Privacy policies permit the use of user content and interactions to operate, evaluate, and improve services as well as their automated systems; sensitive original materials should be submitted only in the minimum amount necessary to complete a task.

Content rating and security rules

The regular worlds suitable for play are intended for individuals over 13 years old, with content that falls within the PG-13 category as a baseline; some of these worlds are labeled as Mature and deal with more mature themes. Being labeled Mature does not mean that explicit sexual content, violent material, or illegal content is allowed – the platform still uses dictionaries, classifiers, and established rules to process the input.

• The world can be marked with warnings regarding strong language, alcohol, drugs, violence, blood, abuse, death, and sexual content.
• Creators can reduce the intensity of violent, offensive, and sexual content, and can also choose more mature themes within the allowed limits.
• The system will adjust inputs that do not meet the current world level to acceptable forms; the filtering is not absolutely precise.
• Sexualization of minors, material depicting child sexual abuse, and sexual content featuring individuals who appear to be minors are strictly prohibited.
• Unwanted private content is strictly prohibited, including AI-generated modifications of real people without their consent.
• It is strictly prohibited to use it for harassment, exposure of private information, threats, terrorism, incitement to crime, and hatred directed at certain groups.
• The generation system must not be used for personalized legal, financial, medical diagnoses, or emergency life-related issues.
• Encouraging content related to self-harm, eating disorders, and suicide will be restricted.

Privacy and data retention

The platform collects account contact information, communication and marketing preferences, player feedback and content, information related to creators’ worlds, subscription bills, as well as creators’ tax and payment details. It also gathers data on devices, browsers, approximate location, and usage and engagement patterns. Payment cards are handled by Stripe, and creators only see aggregated, anonymized data regarding engagement in their respective worlds.

Sales, Advertising, and Privacy Options

The platform does not sell personal information for monetary gain, nor does it share such information for the purpose of displaying ads based on behavior across different contexts; it also respects Global Privacy Control signals in the applicable regions. While ordinary Do Not Track signals are not necessarily responded to at present, users should still manage their data through their accounts, browsers, and privacy settings.

Cross-border processing

Hidden Door is located in the United States; the data of users in other regions may be processed either in the United States or in countries with different data laws. Users in the European Economic Area, the United Kingdom, and Switzerland can, in accordance with the law, submit requests to access, correct, delete, restrict, object to, transfer, and withdraw their consent.

Age and guardian requirements

Supported platforms

Hidden Door primarily runs through modern web browsers; the website offers options for creating progressive web applications that can be installed as separate windows. No official native clients for iOS, Android, Windows, or macOS have been identified.

API, GitHub, and open-source status

No Hidden Door APIs, SDKs, plugin interfaces intended for the public, nor any verifiable official GitHub repository were found. The product’s game engine, narrative composition system, machine learning services, and Atlas are all closed-source online services.

Publicly explaining technical concepts, the boundaries of AI, and content policies does not equate to making the code available for use; there is also no verifiable self-hosted version available. Organizations that wish to integrate this interactive world into their own products must establish the necessary capabilities and obtain the required permissions through IP partnerships or commercial negotiations.

Product advantages

• Using a structured game state to store characters, items, relationships, and events provides greater continuity compared to simply continuing the conversation.
• A combination of artificial narrative pacing, hand-drawn art, and machine learning aims to deliver a controlled entertainment experience.
• Player choices, minor attributes, and dice rolls introduce constraints and the possibility of failure in the story.
• The world, stories, cards, and modifiers create a collectible loop that allows for repeated play.
• The free version does not charge per round, allowing for a complete experience of the story cycle.
• Atlas supports three different starting points: existing writing, creative guidance, and a blank world.
• The world can be listed publicly or privately, making it suitable for personal testing, sharing with friends, and posting in communities.
• The creator retains the rights to the original world and has plans to earn income based on the level of participation.
• Provide a clear commitment for a model that does not require training, regarding collaborative works and the original text to be pasted.

Usage restrictions and precautions

• The generated stories may be incorrect, repetitive, deviate from the character profiles, or contain cultural and training biases.
• The free version allows playing in up to 5 worlds only, with one private message per day to a character, and it is not possible to create new worlds.
• Fan and Creator subscriptions are automatically renewed, and the subscription fees are generally not refundable.
• The earnings for Creators depend on engagement, the formula used for calculation, and payment adjustments; no guaranteed income is provided.
• Creators must be at least 18 years old and meet the requirements regarding identity, taxation, and payment receipt.
• Users retain the rights to their original content, but grant the platform permission to operate it, improve it, and promote it.
• Failing to train external base models does not mean that user interactions are not used to improve internal systems.
• The public world, story highlights, and player variants may remain even after the release is canceled or the project is abandoned.
• The legal basis for fan works and underlying IP is the responsibility of the uploader; platform review does not constitute an authorization certificate.
• The Mature option is still subject to restrictions regarding adults, real persons, minors, and harmful content.
• The product relies on online accounts and third-party generation technologies; there are no publicly available self-hosted or offline solutions.
• Users aged 13 to 17 must have their guardian’s consent; those under 13 are not allowed to use it.

Basic information

Frequently Asked Questions

Is Hidden Door free?

It is possible to play an unlimited number of stories and rounds for free, but only 5 worlds can be selected; private messages to characters are allowed once a day, and the Atlas tool cannot be used to create worlds. Unlimited access to worlds, private messages, and mature content requires a Fan or Creator subscription.

Is it an AI chatbot?

It’s not an ordinary chatbot. It uses a game engine to maintain the state of the world, and it combines scripted narratives, traditional machine learning techniques, a small number of large language model tasks, as well as player choices to create stories.

Can one create their own world?

Yes, the Creator plan offers Atlas; one can start with existing text, a few creative ideas, or a blank canvas, and choose whether to make the content public or private. The creator must possess the rights to the materials and the underlying works.

Can I upload my own novels?

You can paste segments, world settings, or character notes that you are authorized to use as a starting point. The original text pasted is not retained after metadata extraction and is not used for training the model; however, works for which you do not have permission to use should not be uploaded.

Will large models be trained using the author’s books?

Official collaborative works will not be used to train large language models; the team will manually create guidelines for interactive editing. Player-generated content can be utilized for operating, evaluating, and improving the services, but it will not be licensed to third parties for use in training base models that are distributed outside of these services.

Can creators make money?

Creators who are at least 18 years old and meet the program’s requirements can earn a share based on worldwide participation. The amount earned depends on subscription distribution, player engagement, thresholds, taxes, refunds, chargebacks, and changes to the program; therefore, no fixed income is guaranteed.

Will canceling the subscription delete the stories?

It will not be deleted immediately. The stories, progress data, and custom cards remain in the account, but the permission to create them is no longer available; content that has been shared publicly may still be visible.

Can adult content be created?

The paid plan offers a \"Mature\" world along with more adult-oriented themes, but this does not mean that unlimited adult content is allowed. Content that involves minors in sexual contexts, involuntary private images, harassment in real life, and other prohibited types of content must still not be created or published.

Is there a mobile app for Hidden Door?

Currently, it mainly offers Web services along with options for installing PWA configurations. No official native iOS or Android applications have been identified.

Is Hidden Door open source?

No. The game engine, AI systems, and Atlas do not have any publicly available code, nor are there any public self-hosted versions or official GitHub repositories.

Summary

Hidden Door is suitable for those who want to engage in narrative-driven interactions within a world with rules, character statuses, and collectible elements; it also provides writers and world creators with the Atlas tool to turn their original ideas into playable experiences. Its artificial narrative assets, hand-drawn artwork, and structured engine set it apart from endless chat-based formats.

When choosing a plan, it is important to pay attention to the limitations related to the 5 worlds available in the free version and the number of daily private messages, the two different subscription prices, the option for automatic renewal, and the rule that refunds are generally not provided. Creators also need to take into account issues such as IP licensing, operational permits, residual content shared by players, content security, improvements to internal systems, and the uncertainty surrounding revenues.