A flashcard's only job is to force one specific act of retrieval, cleanly, every time it's reviewed — a card that's ambiguous, compound, or answerable by pattern-matching instead of by knowing the fact is a card that will erode trust in the whole deck over hundreds of repetitions.

One atomic fact per card (minimum information principle)

Write each card to test exactly one fact, relationship, or step — not a cluster of related facts bundled because they came from the same paragraph. If answering the card correctly requires recalling three separate things, it's three cards.
When source material presents a fact in a compound form ("X causes Y and Z"), split it into separate cards for X→Y and X→Z rather than one card expecting both in the answer.
A card that's too broad produces partial-credit answers the reviewer has to self-judge inconsistently, which breaks the spaced-repetition algorithm's scheduling — atomic cards get graded cleanly.

Phrase for active recall, not recognition

Write the question so the answer must be produced from memory, not merely recognized among options already present in the question. "What is the capital of France?" tests recall; "Is Paris the capital of France?" tests recognition and is nearly worthless for retention.
Avoid phrasing that leaks the answer's shape or first letter into the question itself — that turns genuine recall into a fill-in-the-blank guessing game.
Prefer specific, answerable questions over vague prompts ("Tell me about the French Revolution") that have no single correct retrieval target — a card needs one right answer, not an essay topic.

Cloze deletion rules

Use cloze deletion ({{c1::term}}) for facts that live naturally inside a sentence of context, and delete only the term actually being tested — not incidental words around it.
Never cloze more than one to two key terms per card; deleting most of a sentence turns the card into a full-recall essay prompt rather than a targeted retrieval cue.
Keep enough surrounding sentence intact that the remaining text still uniquely points to the deleted term — a cloze so aggressive that the sentence could be completed by many different words isn't testing the specific fact intended.

Avoid list-answer cards

Never write a card whose correct answer is an unordered list of several items ("What are the branches of the US government?") — recall of a list is unreliable to self-grade and doesn't scale with spaced repetition. Split each list item into its own card, or number them explicitly if order is the fact being tested ("What is the 2nd branch of the US government, after the legislative?").
If a list must be tested as a set, use a single card only when the count and completeness are the actual fact being memorized (e.g. "How many branches does the US government have?"), not when the items themselves are the target.

Forward and reverse cards

Create both a forward card (term → definition) and a reverse card (definition → term) only when both directions are genuinely useful to know — e.g. vocabulary, translations, or named concepts a learner needs to both produce and recognize.
Skip the reverse card when the reverse direction is trivial, ambiguous (multiple valid terms could fit the same definition), or not something the learner will ever need to do in practice — reverse cards double review load, so only pay that cost when both directions matter.

Context so the card stands alone

Include enough context on the card itself (a date range, a subject tag, a distinguishing detail) that it's answerable correctly months later, disconnected from whatever chapter or session it was written in.
Avoid pronouns or vague references ("this event," "the theory," "he") that depended on surrounding material the reviewer no longer has in front of them — resolve every reference to a specific named thing.
If a fact only makes sense with a specific frame (a particular exam, a particular year, a specific dataset), name that frame on the card rather than assuming the reviewer will remember it.

Prevent pattern-matching instead of knowing

Vary phrasing and question format across cards testing similar material so a reviewer can't answer correctly by recognizing the shape or length of the question rather than knowing the fact.
Avoid systematic tells — always writing the longest answer choice as correct, always using the same sentence template for a given fact type — that let a reviewer "solve" the card format instead of retrieving the actual content.
Periodically rephrase old cards that a reviewer reports as "too easy because I remember the wording" rather than the fact — that signal means the card is testing memorization of the card, not of the material.

Images and mnemonics

Add an image to a card whenever the fact is inherently spatial, visual, or diagrammatic (anatomy, geography, circuit diagrams, chemical structures) — text description of a shape or layout is a weaker retrieval cue than the shape itself.
Use a mnemonic only when the fact is otherwise arbitrary (a sequence, a numeric code, an unordered list that must be memorized in full) — don't force a mnemonic onto material that has a natural logical structure, since the mnemonic then adds a second thing to remember instead of simplifying the first.

Tagging and deck structure

Tag every card with its subject and sub-topic at creation time, not after the fact — untagged cards become unfilterable and unmaintainable once a deck grows past a few hundred cards.
Keep decks organized by subject with consistent naming (Subject::Subtopic) so related cards can be studied, suspended, or exported as a group.
Suspend or delete cards that turn out to be duplicates, ambiguous, or no longer relevant rather than leaving them in rotation — a deck's quality is set by its worst cards, since every card gets reviewed on the same recurring schedule regardless of how good the rest are.

Flashcard Generation Rules