Anki Conditional Card Generation: Add an Optional Question

Three Anki notes can produce four cards: one basic question for each note, plus an application question on the one note that has both an extra prompt and its answer. When you add a note with either extra field empty, Anki skips that additional card.

For this setup, clone Basic, keep its original card type, and add a second card type whose entire front sits inside conditions for both extra fields. The answer field helps decide whether Anki generates the question, but the answer itself stays hidden until you reveal it. No separate enable/disable field is needed.

The three-note rehearsal below ran on October 21, 2026, in a disposable collection using Anki's released Python/Rust backend package 26.9.3, on macOS 26.6.1 arm64 with Python 3.14.7. Desktop instructions were checked against the official manual and release 26.09.3 source; the desktop GUI wasn't tested.

Give the extra question its own fields

A note stores information. Anki uses card templates to turn that information into questions you can review. Here, each note has a core question and, optionally, a separate question that asks you to apply the same fact:

Field	Purpose	Required for this recipe
Front	Core question	Always filled
Back	Core answer	Always filled
ApplyPrompt	Optional application question	Filled only when wanted
ApplyAnswer	Answer to that application question	Must be filled to generate the extra card

A note type defines these fields and its card templates. Editing it affects every note using that type throughout the collection, including other decks. Selecting a deck doesn't limit a template edit. Anki's note-type explanation describes this shared structure.

Start with a new clone and new example notes. Adapting notes you've already studied requires a backup and separate decisions about field and card-type mappings. The add-field guide explains how to isolate a selected group in a clone. Keep reviewed notes out of this rehearsal.

Configure the clone before adding notes

For the full rehearsal, use a separate desktop profile through File → Switch Profile → Add, and leave it disconnected from AnkiWeb. The deliberate empty-card cleanup later belongs in this disposable profile.

1. From Anki's main window, open Tools → Manage Note Types → Add. Choose Clone: Basic for an unmodified Basic type, click OK, and name it Optional application rehearsal. Use a distinct name if that one already exists.
2. Close the manager and open Add. Select Optional application rehearsal as the note type. Open Fields…, then use Add to create ApplyPrompt and ApplyAnswer, with exactly that capitalization. Keep Front and Back, then close the Fields window.
3. Before adding any notes, open Cards…. Keep the original Card 1 as the core question, using the templates below.
4. In the Cards window, choose Options → Add Card Type. Select the new Card 2 and replace its front and back with the application templates below. Save before entering the three notes.

The manual documents cloning and field editing and the Cards window. In released Anki 26.09.3, Add Card Type copies the currently selected template into the new type; replace that copy rather than leaving a duplicate core question. See the released add-card implementation and Options action.

Card 1: keep the core question

Front Template:

{{Front}}

Back Template:

{{FrontSide}}
<hr id=answer>
{{Back}}

Keep this first card type in place. Its question remains available independently of the optional fields, provided Front is filled. Fill Back too: this core template doesn't check whether its answer is empty.

Card 2: require both application fields

Front Template:

{{#ApplyPrompt}}
{{#ApplyAnswer}}
{{ApplyPrompt}}
{{/ApplyAnswer}}
{{/ApplyPrompt}}

Back Template:

{{FrontSide}}
<hr id=answer>
{{ApplyAnswer}}

{{#ApplyPrompt}} includes the enclosed template content when ApplyPrompt is nonempty. The nested {{#ApplyAnswer}} condition requires the answer field too. Only {{ApplyPrompt}} is printed on the front; {{#ApplyAnswer}} tests for content without printing the answer. Field names are case-sensitive.

This is Anki conditional card generation built with conditional replacement. The conditions control what the front displays and, because they enclose the whole front, whether Anki generates a new card. Putting the checks only on the back can still create a question with no answer. Keep the entire application front inside both conditions, including any labels or extra text you add later. Anki documents both requiring two fields and avoiding blank backs.

Add these three notes and expect four cards

Enter the examples as plain text. Add the tag conditional-rehearsal to each note, and leave fields marked “empty” blank. Don't type the word empty.

Note	Front	Back	ApplyPrompt	ApplyAnswer
A	How many centimeters are in one meter?	100 cm	A ribbon is 2.4 m long. How many centimeters is that?	240 cm
B	How many seconds are in one minute?	60 s	empty	180 s
C	How many grams are in one kilogram?	1000 g	A bag has a mass of 1.5 kg. How many grams is that?	empty

B's lone answer and C's lone prompt deliberately test incomplete pairs. They aren't finished application questions.

Open Browse and search tag:conditional-rehearsal. Confirm the search finds only these examples. Compare Notes and Cards modes:

Note	Core card	Application card	Initial total
A	Present	Present: both fields filled	2
B	Present	Absent: prompt missing	1
C	Present	Absent: answer missing	1

The result is three notes and four cards. In Cards mode, select each row and use Preview to check its question and revealed answer. Notes mode previews only the first card of each note, so use Cards mode to check the application card too. See Browser preview.

A's application front should show the ribbon question without 240 cm; revealing the answer should show 240 cm. The backend rehearsal checked that exact separation. If an intended card exists but its question is invisible, use the blank-card diagnosis before deleting it.

Fill a missing answer, then clear a different one

In Browse, set C's ApplyAnswer to 1500 g and finish editing the note. Anki generates C's application card automatically. You now have five cards, and its new question should appear in Cards mode Preview.

Next, in this disposable rehearsal only, clear A's ApplyAnswer. Its existing application card remains. The count stays five, even though the condition now fails. The backend returned Anki's built-in “The front of this card is blank” warning for that card. An empty card can display that warning rather than a completely blank screen.

Anki generates newly eligible cards when a note changes, but keeps previously generated cards that become empty to avoid accidental deletion. Removing those cards is a separate action. These are the documented generation and deletion rules.

Rehearsal stage	A cards	B cards	C cards	Total
Initial three notes	2	1	1	4
Fill C's ApplyAnswer	2	1	2	5
Clear A's ApplyAnswer	2	1	2	5
Remove A's reported empty application card	1	1	2	4

Decide whether to pause or remove a question

If you want to pause A's application question, restore its ApplyAnswer to 240 cm and suspend that individual card. For real notes, keep both application fields filled when suspending. Suspension keeps the card available for later; the bury versus suspend guide shows how to select it separately from its core sibling.

For an obsolete application question, save any field text you want to keep before clearing a required field. Then use Tools → Empty Cards. Inspect every entry before deleting anything: this report covers the whole collection, and your Browse search doesn't limit it. The desktop dialog deletes cards from the whole report; it doesn't let you select just A's row. If unrelated cards appear, close the dialog and investigate them first. See the released Empty Cards dialog.

In the disposable profile, proceed with deletion only if the report contains A's application card and nothing else. Return to Browse and confirm that the tag search now finds three notes and four cards, including A's core question.

In the backend rehearsal, the empty-card report contained only A's application card. Removing that reported card left all three notes and all three original core card IDs intact. The final count was four. This verifies those counts and IDs; the run didn't test review scheduling or history preservation, mobile clients, sync, or desktop interaction.

Never use Browser Delete just to remove this optional question: it deletes the note and its sibling cards. Anki documents note deletion in Browse.

There is also an all-empty-note exception. Adding a new note whose templates generate no questions creates a placeholder using the first card type. The backend rehearsal confirmed this too. Keep Front populated in these examples so that exception doesn't interfere with the optional-card check. See adding empty notes.

Once the disposable rehearsal matches the counts and previews, create the same type in your normal collection for new notes. Before changing a real collection's structure, sync outstanding work from other devices and save a collection backup. Structural edits can require a one-way sync; if prompted, use the upload-or-download guide to identify the collection containing the work you intend to keep. Leave the rehearsal profile unsynced.

AI agents researched and wrote this guide and ran the disposable backend rehearsal described above. The illustration is AI-generated. Nibomo publishes this guide and also makes a flashcard app; this procedure works entirely in Anki.