What broke, dated. On 20 Aug 2026 the one-page sheet in this kit became two pages while the read-me kept calling it one. The sheet shipped that day; the read-me and the cards booklet caught up on 17 September 2026, when the rebuilt kit replaced the download. The Copilot kit that tells you what works, what doesn't, and when to close the tab.You probably tried Copilot already. A few good summaries, a few confident but wrong answers, and then the tab went quiet. That is not a you problem. Most Copilot guidance shows the demo and skips the failure modes, so you find the edges the hard way. This kit is the honest version: every app card names the 3 prompts that work, the 3 mistakes that waste your time, and what to skip Copilot for entirely. There is a whole chapter on when not to use it at all. One tier, $39, everything included.Every app card carries a "Skip it for" line. The promise isn't that Copilot is magic. It's that you'll know exactly where it helps, where it doesn't, and how to tell a good answer from a plausible wrong one.I'm an independent practitioner, not a Microsoft employee, partner, or reseller. I deploy Microsoft 365 Copilot inside an engineering company and maintain open libraries of Copilot prompts and agents used by thousands of practitioners. I have no licence to sell you, only what actually works."Battle-tested in production environments." That is how Jared Spataro, Microsoft's CMO for AI at Work, described my public Copilot prompt library. These cards are the judgment layer around that library, held to the same standard.What's inside 14 reference cards: 5 durable Foundations + 9 app cards (Outlook, Word, Excel, PowerPoint, Copilot Chat, Notebooks, Cowork, Teams, Researcher & Analyst). Each card gives you when to use it / skip it for, the 3 prompts that work, the 3 mistakes to avoid, and a one-line "Remember." So you stop guessing and start with what's already been tested. "Copilot on One Page": the wall sheet: THE LOOP (Ground → Draft → Check → Decide), THE PROMPT (Goal · Context · Source · Format), THE RULE ("AI prepares. You decide."), and THE 3 RISKS (Hallucination · Mis-citation · Over-trust). The page you tape to the wall and stop relearning. The guide, as a two-week plan (~33 pages): day one is a real win in 10 minutes, then ten drills of ten minutes each across two weeks, ending in a scored proficiency self-check so you can measure the change. Around the drills: Start Here (a 5-minute path), the one chapter on how to get a good answer every time (prompt + ground + verify), "When NOT to use Copilot," and "Data, trust & the EU boundary." One of the cards, openedHere is the Outlook card doing its job. You ask for a summary of a forty-message thread. It comes back clean, and it misses the reply where the decision was reversed. The fix on the card's first mistake is mechanical, and it is built for exactly this: click the numbered citations against the original. The card also carries the prompt that asks Copilot to flag what it could not verify, so the trap gets smaller before you even check.The GitHub libraries are prompts. These cards are the other half: when the prompt is the wrong move, how to check the citation, and which work must stay off Copilot. That is the part you cannot get from a prompt pack.Who it's forAnyone with a Microsoft 365 Copilot licence who wants to be genuinely good at it, fast: PMs, finance, ops, HR, executive assistants, managers, and consultants.Who it's not for IT admins deploying or governing Copilot across a tenant: this is about using it well, not rolling it out. Executives evaluating whether to buy Copilot: this assumes you already have a licence. Running the rollout itself rather than just using the licence? Then this is the smaller tool. The M365 Copilot Deployment Kit ($97) is built for the person deploying Copilot across a tenant; this kit is for the people using it once it lands.PricingOne tier: $39. The guide, all 14 cards, and the wall sheet. 14-day refund, no questions: if the kit does not make you better at Copilot, email and get your money back, and keep the files. Buying for a team? Email mathieu@kesslernity.com for a team quote.Licensed, not sold. Full License & Terms apply: https://www.kesslernity.com/license (ref KESS-LIC-2026-001). By purchasing you agree to the version in force on your purchase date.Kesslernity is an independent publisher: this product is independent analysis, not affiliated with, sponsored by, or endorsed by Microsoft. Microsoft 365 and Copilot are trademarks of the Microsoft group of companies. It is practitioner guidance, not professional, legal, or financial advice.Questions before you buy, or support after? Contact mathieu@kesslernity.com.Terms of Service · Privacy Policy Checked against Microsoft's own pages before publication. Since August 2026, three rival labs' models try to break every listing before I decide what ships. Misses, dated, with fixes: kesslernity.com/what-broke