Terms of Service

These Terms of Service ("Terms") govern your use of Stack Check (the "app," "Service," "we," "us"). By accessing or using Stack Check, you agree to be bound by these Terms — a legally binding agreement between you and us. If you don't agree, please don't use the app.

We may update these Terms as the app evolves. Changes are reflected by updating the "Last updated" date above; for material changes, we'll make reasonable efforts to surface a notice in the app itself. Continuing to use the app after changes take effect means you accept the revised Terms.

These Terms are governed by the laws of the State of Indiana, United States, without regard to conflict-of-law principles. Your use of the Service may also be subject to other local, state, national, or international laws.

1. Definitions

• "Service" refers to Stack Check, including all content, features, and functionality provided through mtgstackcheck.com.
• "User" means any individual who accesses or uses the Service.
• "Content" includes rules text, card data, analysis results, and other information provided through the Service.
• "User Content" means decklists, questions, card photos, and any other material you submit through the Service.

2. What Stack Check is

Stack Check is an unofficial, fan-made companion tool for Magic: The Gathering, providing Comprehensive Rules search, card lookups, Commander Bracket/Game Changer reference, AI-assisted deck analysis ("Rule 0"), and AI-assisted rules Q&A ("Ask a Judge"). Rules search, card text lookups, and the Brackets/Game Changers/banned-list reference are free and don't require an account. The AI-assisted features use a monthly usage allowance ("Mana") tied to your account tier.

Technical requirements

Using Stack Check requires a modern web browser and an internet connection. No special software or hardware is needed beyond that (a camera is used for the optional card-scanning feature, if you choose to use it).

Availability

We aim to keep the Service reliably available, but — like any small, independently-run web application — don't guarantee uninterrupted uptime, and are not liable for temporary unavailability, including from scheduled maintenance or issues with third-party services we depend on (see Section 8).

3. Accounts

• You must provide accurate information when creating an account and are responsible for keeping your login credentials secure.
• You're responsible for all activity under your account.
• You must be old enough to legally agree to these Terms in your jurisdiction, and in any case not under the age of 13.
• One account per person. Accounts are not transferable.
• The Service is generally available worldwide; we're not currently aware of any territory where it can't be used, though this could change if a future dependency (e.g., a payment processor) has its own geographic restrictions.

4. Subscriptions, tiers, and Mana

• Stack Check offers multiple tiers (currently Common, Uncommon, Rare, and an invitation-only Mythic tier), each with a different monthly Mana allowance for AI-assisted features.
• Paid tiers are billed on a recurring monthly basis, in USD, through Stripe, our payment processor. By subscribing, you authorize recurring charges until you cancel.
• Cancellation: you can cancel a paid subscription at any time through the in-app subscription management link. Cancellation takes effect at the end of your current billing period — you keep access through the period you've already paid for, and won't be charged again.
• Refunds: subscription charges are generally non-refundable, including for partial billing periods, except where required by law.
• Failed or late payments: if a payment fails, Stripe will attempt to retry it automatically; if it continues to fail, your account reverts to the free Common tier rather than accruing a balance or fee.
• Changes to pricing or tiers: we may adjust tier pricing, Mana allowances, or feature costs going forward. We'll make reasonable efforts to communicate material changes, but existing billing periods already paid for won't be retroactively affected.
• Unused Mana does not roll over between billing periods and has no cash value.

5. Acceptable use

You agree not to:

• Attempt to circumvent Mana limits, rate limits, or tier restrictions.
• Use automated tools to scrape, bulk-query, or abuse the app's AI-assisted features beyond normal individual use.
• Reverse-engineer, decompile, or attempt to extract the app's underlying prompts, source code, or infrastructure beyond what's already publicly visible in your browser.
• Use the app for any unlawful purpose, or to harass, abuse, or harm others.
• Resell, sublicense, or provide access to your account or its Mana allowance to others.

We reserve the right to suspend or terminate accounts that violate these terms.

6. AI-generated content — read this part

7. Intellectual property

• Magic: The Gathering, its card names, rules text, and related intellectual property are owned by Wizards of the Coast LLC. Stack Check is unofficial Fan Content permitted under Wizards' Fan Content Policy, is not approved or endorsed by Wizards, and makes no claim of ownership over any Magic: The Gathering intellectual property.
• Paid tiers on Stack Check are charges for the hosting, computation, and AI-assisted services we provide — not for access to Wizards' rules text or card data itself, which remains free to look up within the app regardless of tier.
• The Stack Check name, branding, and the app's own original code and design are ours (or licensed to us), separate from any Magic: The Gathering IP referenced within it.

8. Data protection and third-party services

For complete information about our data practices, see our Privacy Policy. In brief: data is encrypted in transit, account credentials are managed entirely by our authentication provider (we never see plain-text passwords), and we don't sell your information.

Stack Check relies on third-party services to function, including:

• Anthropic (Claude) — powers the AI-assisted features
• Scryfall — card data lookups
• Supabase — database and authentication
• Stripe — payment processing
• Vercel — application hosting

We don't control these services and aren't responsible for their availability, accuracy, or downtime. If a third-party service is unavailable, some or all of the app's features may be temporarily degraded or unavailable.

9. Disclaimers and limitation of liability

Warranty disclaimer

Stack Check is provided "as is" and "as available," without warranties of any kind, express or implied, including warranties of merchantability, fitness for a particular purpose, or non-infringement.

Limitation of liability

To the fullest extent permitted by law, we are not liable for any indirect, incidental, special, or consequential damages arising from your use of the app, including but not limited to reliance on AI-generated rules content, service interruptions, or data loss. Our total liability for any claim relating to the app is limited to the amount you paid us, if any, in the 12 months preceding the claim.

Indemnification

You agree to indemnify and hold us harmless from any claims, damages, or expenses (including reasonable legal fees) arising from your violation of these Terms, your User Content, or your use of the Service.

Force majeure

We are not liable for any failure or delay in the Service caused by circumstances beyond our reasonable control, including natural disasters, government actions, internet service provider failures, or third-party service outages (see Section 8).

10. Termination

• You may stop using the app, cancel your subscription, or permanently delete your account at any time through the in-app account settings.
• We may suspend or terminate your access for violating these Terms, at our discretion.
• Account deletion is immediate and permanent — saved decks, favorites, and subscription history are deleted and cannot be recovered.

11. Contact

Questions about these Terms: mtgstackcheck@gmail.com

For bugs or app issues, please use the "Report a problem" link in the app instead.