How to Write Good Flashcards: 12 Rules With Before-and-After Examples

TL;DR. Good flashcards are small, specific, and unambiguous: one fact per card, one right answer, and a question you'd understand without context. The best-known statement of this is the "minimum information principle" from Piotr Wozniak, creator of SuperMemo, in his rules for formulating knowledge. Below are 12 rules with before-and-after cards. They apply whether you write cards by hand or edit a deck from an AI flashcard maker, and they matter more when you use spaced repetition, because a bad card gets shown to you over and over.

Why card design matters so much

With spaced repetition, a card you know well disappears for weeks. A card you keep failing comes back tomorrow. So bad cards (vague, overloaded, ambiguous) quietly take over your review time. Fixing ten bad cards can save more time than any scheduler setting.

Good cards also make the retrieval itself work. The whole point of a flashcard is active recall: pulling a specific answer from memory. A card that allows five acceptable answers doesn't train any one of them.

Rule 1: One fact per card (minimum information)

Before

After

Four small cards are faster to review than one big card you half-remember.

Rule 2: One right answer

Before: "What is important about the Treaty of Versailles?" There are a dozen right answers.

After: "Which treaty formally ended World War I between Germany and the Allies?" Back: the Treaty of Versailles (1919).

If you ever find yourself saying "well, I sort of got it," the card has more than one answer.

Rule 3: Avoid lists (sets and enumerations)

Lists are the classic bad card. "Name the seven SI base units" fails every time you forget one.

Options:

Rule 4: Make it context-free

Cards turn up shuffled weeks later. "What does it inhibit?" meant something on lecture day and nothing in November.

Before: Front: What does it inhibit? Back: COX-1 and COX-2

After: Front: Which enzymes does aspirin inhibit? Back: COX-1 and COX-2 (irreversibly)

Rule 5: Ask in both directions when both matter

For vocabulary, "perro → dog" and "dog → perro" test different skills: recognition and production. Make both only when you need both. For most science definitions, one direction is enough. More in the vocabulary flashcards guide.

Rule 6: Prefer "why" and "how" cards for understanding

Pure recall cards are fine for facts. Add a few cards that force reasoning.

Keep them short, and keep the answer to the core mechanism.

Rule 7: Use your own words

Cards copied verbatim from a textbook often test whether you can recall a sentence, not whether you know the idea. Rephrase in the words you'd use explaining it to a friend. When an AI drafts your deck, this is exactly what the edit pass is for.

Rule 8: Add a cue, not a hint that gives it away

Too vague: "Capital of Australia?" (fine, actually, but many people answer Sydney)

Good cue: "Capital of Australia (not the largest city)?"

Gives it away: "Capital of Australia (starts with Canb-)?"

Cues narrow the question; hints answer it.

Rule 9: Include an example on the back

Examples make the answer stick and help you check yourself.

Rule 10: Don't make cards for things you already know

Every card costs future review time. If you've known it for years, skip it. This is the fastest edit you'll make on an AI-generated deck.

Rule 11: Split, rewrite, or delete leeches

If a card has failed five or more times, it's badly designed. Ask why: too much information? ambiguous? confusable with a similar card? Then split it, add a distinguishing cue, or delete it. The how many flashcards per day post shows how much leeches cost.

Rule 12: Learn first, card second

Flashcards are for keeping what you understand, not for understanding it in the first place. Read, listen, or work through the topic, then make cards. Cards made from material you don't understand are memorised strings.

A quick checklist for every card

Applying the rules to AI-generated decks

AI generators are good at first drafts and average at the rules above. In our experience, the common issues are cards that combine two facts, fronts that are too general, and cards on trivia you already know. The fix is a five-minute edit pass.

In SimpleQuizMaker you generate a deck of 5 to 50 cards (up to 20 on the free plan, 50 on Student) from a topic name or from up to 50,000 characters of pasted notes, then edit or delete any card. A good routine:

If some material doesn't fit flashcards (application, multi-step problems), generate a quiz from the same notes in the quiz maker instead. See flashcards vs practice quizzes for how to split.

One limitation worth knowing: SimpleQuizMaker doesn't support image cards or image occlusion, so rules about picture cards apply to tools like Anki, not to us.

Try the rules on one deck

Paste one lecture's notes into the free flashcard maker, then run the checklist above on every card. You'll probably cut a quarter of them and rewrite another quarter, and the deck that's left will take noticeably less time to review.