마지막 업데이트: August 8, 2026
By accessing or using Underfiction ("the Service"), operated at underfiction.com, you agree to be bound by these Terms of Service. If you do not agree, do not use the Service.
Underfiction is an AI-powered interactive fiction platform. You provide input and AI models generate narrative prose — and, where you request it, images and video — in response. The Service uses third-party AI inference providers to generate content.
You must be at least 18 years old to use the Service. By creating an account, you confirm that you are 18 or older.
Content generated by the Service is produced by third-party AI models: large language models for prose, and image and video generation models for visual content. While the Service does not apply automated content filters beyond those of its inference providers, all use remains subject to the Acceptable Use policy in Section 7. You acknowledge and agree that:
AI-generated content may be inaccurate, inappropriate, offensive, or otherwise unexpected. Generated content does not represent the views, opinions, or endorsements of Underfiction or its operators. You are solely responsible for how you use, share, or publish any content generated through the Service. AI models are non-deterministic — the same input may produce different output on different occasions. We make no warranties regarding the quality, accuracy, creativity, or suitability of any generated content.
Generated images and video are synthetic media. They may carry a visible mark identifying them as AI-generated; you may not remove such marks, and you may not present generated images or video as authentic recordings of real people or events.
You may create an account using email and password, Google, or Apple sign-in. You are responsible for maintaining the security of your account credentials. You must provide accurate information and promptly update it if it changes.
You may delete your account at any time from your account settings. Deletion removes your account data, usage records, published items, shared excerpts, synced stories, characters, and worlds, and your uploaded images and video from our servers. Data stored on your devices remains in your browser or app until you clear it. Account deletion is permanent and cannot be undone.
Deleting your account takes your published items off our servers. It does not reach copies other people already imported: those are independent local copies on their own devices, and we have no way to recall them. Section 11 describes what an import is.
The Service operates on a pay-per-use system using credits, an in-app currency. Credits are purchased in advance and consumed as you use the Service.
Credit purchases are processed by Stripe. By purchasing credits, you also agree to Stripe's terms. Credit purchases are non-refundable except where required by applicable law. We reserve the right to modify credit pricing at any time. Existing purchased credits will not be affected by price changes. Unused credits do not expire while the Service is operational. In the event the Service is discontinued, we will provide reasonable notice and, where feasible, an opportunity to use remaining credits.
You agree not to use the Service to:
Generate any sexualized depiction of a minor — real or fictional, in any medium, including characters presented or described as minors. Generate or animate intimate or sexual imagery of a real, identifiable person without that person's consent. Upload images of real people without their consent, or images you do not have the right to use. Generate content for the purpose of harassing, threatening, or intimidating real individuals. Deceive others by presenting generated content as authentic, including impersonating real people. Publish a world, character, or story you do not hold the rights to publish. Attempt to reverse-engineer, exploit, or attack the Service or its infrastructure. Resell, redistribute, or commercially exploit AI-generated output as an automated service. Violate any applicable law or regulation.
If you publish, you publish under a pen name. Your pen name is public and appears on every item you publish. Do not take a pen name that impersonates a real person, another user, an organization, or Underfiction itself, and do not use one to harass anyone or to carry a slur. We reclaim pen names that break this rule, and we may reclaim one that misleads readers about who made an item.
We reserve the right to suspend or terminate accounts that violate these terms without prior notice or refund, to remove any content you have uploaded to our servers, and to report violations to the competent authorities where we are legally required to do so.
If you believe that content uploaded to, generated through, or published on the Service violates these Terms or your rights — in particular intimate imagery of you created or shared without your consent — report it to [email protected]. We review reports promptly, prioritize reports of non-consensual intimate imagery, and remove reported content hosted on our servers within 48 hours of a valid report.
Published items and pen names can also be reported from the Service itself. An item that enough distinct people report is hidden pending review. Removing an item takes it off our servers; it does not reach copies other people already imported.
You agree to indemnify and hold harmless Underfiction and its operators from and against any claims, damages, liabilities, costs, and expenses (including reasonable legal fees) arising out of the input you provide, the content you generate, your use of the Service in violation of these Terms, or your infringement of any third-party rights.
You retain ownership of the input you provide. AI-generated output is provided as-is. We make no claim of ownership over generated content, but we also make no guarantee of its originality or that it does not infringe on third-party rights. You are responsible for ensuring your use of generated content complies with applicable intellectual property laws.
When you publish a world, character, or story, you keep ownership of it. You grant Underfiction a worldwide, non-exclusive, royalty-free, transferable and sublicensable license to store, host, reproduce, display, and distribute that item, and to let other users copy it into their own libraries, edit those copies, and make derivative works from them — their own versions, and the stories they write with it. The right to sublicense is what makes an import possible at all: every copy a reader takes runs on that permission.
The license runs for as long as the item is on our servers and, for copies already imported, for as long as those copies exist. You can revoke an item at any time. Revocation stops us serving it and stops new copies being made; it cannot reach a copy someone already holds.
When you publish an item you confirm that it is yours to publish or that you hold the rights to publish it, that it depicts no real, identifiable person in a sexual context, and that it depicts no minor sexually — in any medium, including characters presented or described as minors. We remove items that break these rules and may terminate accounts that keep publishing them.
Stories, characters, worlds, and their images and video are stored on your device and, while sync is on, on our servers so they reach your other devices. Sync is on by default and can be turned off in Settings. Stories are encrypted at rest with a per-user key wrapped by a server-held key; we hold the means to decrypt them and do not do so outside of operating the service. You can export portable .underfiction archives whether sync is on or off.
Older releases used a separate system for character and world image uploads. Those legacy uploads are not used by current clients. They are removed when you delete your account or ask us to remove them.
If you deliberately publish a shared excerpt, you instruct us to store and serve a plaintext copy of the exact excerpt and continuation data shown in the publish preview. Anyone with the unlisted link can read the excerpt, retrieve its enabled continuation data, and use it to begin a new local story. Shared excerpts are not encrypted at rest because the server must serve them publicly. You can revoke a link from account settings; revocation does not remove copies or cached link previews already obtained by others.
If you publish a world, character, or story, you instruct us to store and serve a plaintext copy of it: its text, its images, its tags, and your pen name. Published items are not encrypted at rest, because the server has to serve them publicly. A listed item is readable by anyone browsing the Service; an unlisted one is readable by anyone holding its link.
An import is a fork, not a subscription. When someone imports your item, it becomes a full, independent copy on their device. Edits you make later never reach it. Revoking the item, deleting it, or deleting your account never reaches it either — those copies stay where they are, and we have no mechanism to recall them. Publish on that basis.
You acknowledge that with sync turned off, clearing your browser data, deleting the app, or switching devices may result in the permanent loss of content held only on that device. We are not responsible for data loss resulting from browser or app storage limitations, clearing, or corruption, nor for loss of content that was never synced. It is your responsibility to preserve content you wish to keep, including by leaving sync on or exporting a portable archive before clearing local data.
To the maximum extent permitted by applicable law, Underfiction and its operators shall not be liable for any indirect, incidental, special, consequential, or punitive damages, including but not limited to loss of data, loss of profits, or damages arising from use of or inability to use the Service, any content generated by the Service, unauthorized access to or alteration of your data or transmissions, loss of locally stored or cloud-synced content, or any third-party conduct or content including AI inference providers.
The Service is provided "as is" and "as available" without warranties of any kind, whether express or implied.
The Service relies on third-party providers for AI inference, payment processing, and authentication. We are not responsible for the availability, performance, or policies of these third-party services. Your use of the Service constitutes acceptance of the terms and privacy practices of these providers insofar as they apply to your use.
We do not guarantee uninterrupted or error-free operation of the Service. We may modify, suspend, or discontinue any part of the Service at any time without prior notice. We are not liable for any modification, suspension, or discontinuation.
We may update these Terms at any time. Continued use of the Service after changes are posted constitutes acceptance of the revised Terms. We encourage you to review this page periodically.
These Terms shall be governed by and construed in accordance with the laws of Switzerland. Any disputes arising from these Terms or the Service shall be subject to the exclusive jurisdiction of the courts of Zürich, Switzerland.
If you have questions about these Terms, you can reach us at [email protected] or through our Discord.