By the end you'll know what each card level means, what your flashcard answers do to the next review date, and why a card sometimes comes back sooner than you expect.

What you need

• A deck with at least one card you've studied.
• Nothing else. There's no setting to switch on. Every deck is scheduled this way.

1. Open the level explainer

On a deck page, find the Learning Progress panel with the colored level bar. Click How it works in its corner, or anywhere on the panel.

A window titled How learning works opens. It lists the six levels and how reviews are scheduled.

Note: On iOS and Android, tap the Learning Progress card on the deck screen. The window has the same title and the same six levels. The Extra practice section described in step 6 is on web only.

2. Read the six levels

Every card sits on one of six levels. The first two depend on whether you've studied the card and whether you last missed it. From Familiar up, the level depends on how long the card's current gap between reviews is.

3. Answer the flashcard: that's the only grade

There are no difficulty buttons to rate yourself with. You say whether you knew the card, and Vocards works out the next gap from that.

• On web, click Got it! or Not yet, or swipe the card right or left.
• On iOS and Android, the buttons are Got it! and Not yet.

A card that's due or new is always shown as a flashcard until you get it right. Multiple choice, gap-fill and typed answers only turn up after that, or on practice cards (see step 6). They're extra practice:

• A wrong answer on one of them never counts against the card.
• A right answer on one of them never moves the card up.

4. What a right or wrong answer does

When you know it, the card leaves the session and gets its next date:

1. The first time you answer it correctly, it comes back after 1 day.
2. The second time, after 6 days.
3. After that, the new gap is the last gap multiplied by the card's growth factor. Every card starts at 2.5.

The gap keeps widening until it reaches 180 days, and the card becomes Mastered. How fast it gets there depends on the growth factor, so there's no fixed number of reviews.

When you don't know it, it stays in the session and comes back a few cards later. What else happens depends on its level:

• An Unseen card moves to Learning.
• A card on Familiar or higher drops to Learning at once. Its gap is cleared, and its growth factor goes down.

Answer it correctly later in the same session and it leaves as Familiar, due again in 1 day. The ladder starts over from the bottom.

5. Why hard cards come back sooner

A card you keep missing is scheduled more tightly:

• A miss restarts the ladder. Even a Mastered card goes back to 1 day, then 6.
• Its gaps grow more slowly afterwards. The growth factor goes down when you miss a card that was already on the schedule. It goes down a little more when you miss a card once or twice in a session before you get it right. It never drops below 1.3.

If you miss the same card three times in one session, it still leaves the session when you finally get it right. It stays on Learning and doesn't move up. You'll see it again next session.

Cards you keep getting right go the other way: each clean answer multiplies the gap again, so they turn up less and less often.

6. Why you can see a card you already answered today

The web explainer has a section for this, under Extra practice. These are the cases:

• You missed it. A missed card comes back a few cards later in the same session.
• The session is almost over. When only one or two cards are left, cards you already cleared are mixed back in, often as a different exercise. They don't change your schedule.
• The session was topped up. A session tries to reach your Cards per session number. If fewer cards are due or new, and at least one is, it fills the empty places with cards that aren't due yet, closest to their date first. Those are free practice. Answering them doesn't change their level or their next date, and they never take the place of a card that's due.
• It's on Learning. A Learning card is due straight away, so it can come back in your next session the same day. If you study the same deck twice in a day, the second session picks cards you haven't seen today first. Due cards you've already practiced only fill the places left over.
• You studied late at night. See the next step.

7. When a new study day starts

A study day runs from 4:00 AM to 4:00 AM in the time zone saved in your settings. Due dates are whole days: a card that comes back "in 1 day" is due from 4:00 AM on the next study day.

That can make a gap feel shorter than it is:

• Answer a card at 11 PM and it's due again at 4 AM the next morning.
• Answer it at 1 AM and that still counts as the day before, so it's due again at 4 AM the same night.

A session you leave open past 4:00 AM is closed. The answers you already gave are kept.

8. Set how many cards a session holds

Cards per session in Settings sets the size of each session. It's 10 by default and goes from 5 to 100.

Each session takes due cards first, then new cards, up to that number. A bigger number doesn't bring cards back sooner. It only fits more of them into one sitting.

What you'll see

• The level bar on each deck page shows how many cards are on each of the six levels.
• On Home, once a card has moved up today, Moved up today shows how many did. Click it to see which words.
• Level history on the stats page shows where each day left a word, up or down.

On iOS and Android the same rules run in sessions you study offline.

Limits

• Only flashcard answers change a card's schedule.
• A card's gap is counted in whole study days. You can't schedule a review for a time of day.

If something goes wrong