Terms of Service
Effective date 2026-10-12
The Black Grimoire's deck tools are provided as-is, with no warranty of any kind, and stay free: see "Paid plans" below for the only thing money buys on this site. Deck suggestions are generated from a statistical model and a rule-based synergy graph over public decklist data, so they are not guaranteed to be optimal, legal in every format, or accurate at every moment the underlying card data changes.
Use of the service
You may use the builder, catalogue, and collection viewer for personal deck building at no cost. Automated scraping of this site, or request volume against the build or feedback endpoints beyond normal personal use, may be rate-limited or blocked without notice to keep the service usable for everyone else.
Accounts, and no guarantees
The builder, optimizer, Deck Doctor, and collection all work with no account. An account (via Clerk) is needed for the dashboard, saving decks, match history and Arena matches, desktop sync, the AI consultant, and a paid plan; your collection also syncs to the account when you are signed in, on top of staying in your browser. Signing in creates a server-side row for your email, plan, Stripe customer/subscription IDs, AI usage counts, saved decks, your collection, match history, and desktop sync tokens — see the Privacy Policy for the full list. Data stored only in your browser is your responsibility to back up; the developer cannot recover it if it is lost, and there is no restore or export tool beyond what the collection page provides.
Accuracy and liability
Card legality rules, prices, and availability change over time, and while the underlying card database is refreshed regularly, it can lag behind the newest official rulings or bans. The developer is not liable for any loss arising from reliance on a build, an export, or an analysis produced by this site.
Paid plans
Every deck tool — the builder, optimizer, Deck Doctor, collection and decks — stays free and uncapped. The Pro ($4.99/month) and Commander ($14.99/month) plans only raise your monthly allowance of AI deck consults on Claude (Anthropic) and your daily allowance of best-deck runs (Free 3, Pro 15, Commander 50 per day); past the consult allowance the consultant still answers, using a standard OpenAI model instead. Payments are processed by Stripe as a recurring monthly subscription. You can cancel at any time from the billing portal (Dashboard → Manage subscription); cancelling sets the subscription to end at the close of the billing period you already paid for, rather than immediately, and there are no partial-month refunds beyond what is described below. EU and UK consumers can cancel within 14 days of first subscribing and get a refund on request through the contact page. Because the service starts immediately at checkout rather than waiting out that 14 days, any refund under this right may be reduced in proportion to the period of service you already used.
Wizards of the Coast
The Black Grimoire is unofficial Fan Content permitted under the Fan Content Policy and is not approved, endorsed, sponsored, or specifically approved by Wizards of the Coast. "Magic: The Gathering" and related marks are trademarks of Wizards of the Coast LLC, used here for identification purposes only. See the site footer for the full notice.
Changes
These terms may change as the site adds features such as advertising or new formats. Continued use of the site after a change is published means you accept the updated terms, and the effective date at the top of this page will move forward whenever that happens.