How it works
How MemDecks decides when a card comes back
No — not in the sense the term usually carries. MemDecks stores no review intervals, no ease factors and no next-review dates, and it has no "due today" queue. A card comes back because a game drew it from your collection, and games draw from everything you own. What decides whether a card still needs work is card HP: a practice budget assigned per word, spent by correct answers.
What MemDecks does instead
Every MemDecks card is created with a fixed practice budget called card HP, between 100 and 500, derived from how difficult that word is in your study language. Every correct answer in a game adds score to the card. Progress is score ÷ card HP. A card is finished when the budget is spent.
So the question MemDecks answers is not "when should this come back" but "how much work does this word still owe". Cards with unspent budget keep appearing because games keep drawing from your collection; cards at 100% keep appearing too, but they no longer represent outstanding work.
How this differs from Anki-style spaced repetition
| Interval-based SRS (Anki, SuperMemo) | MemDecks | |
|---|---|---|
| Unit of state | Interval, ease factor, next review date | Score and card HP |
| What triggers a repeat | A date arriving | A game selecting the card |
| If you skip a week | A backlog of overdue cards | Nothing accumulates |
| Difficulty input | How you rated your own recall | A per-language difficulty score of the word itself |
| Optimises for | Retention per review | Practice actually happening |
Why MemDecks was built this way
Interval scheduling is well evidenced and MemDecks does not dispute it. The trade it makes is different: an SRS produces a daily obligation, and an obligation missed becomes a backlog, and a backlog is the single most common reason people abandon a vocabulary tool. MemDecks is built for the learner who returns irregularly. Nothing rots while you are away, and there is no number counting up to shame you back.
The cost is real and worth stating: MemDecks does not time your repetitions for maximum retention. If your goal is to memorise five thousand cards before an exam on a fixed date, an interval scheduler will do it more efficiently. MemDecks optimises for a different thing — that the practice happens at all, and that it is pleasant enough to repeat.
Where the difficulty number comes from
Card HP is round(difficulty tier × 4.2), floored at 100 and capped at 500. Difficulty tiers run 0 to 100 and are computed offline, per word and per language, by a scoring pass that weighs how rare the word is, how long and orthographically awkward it is in the target script, how many senses it carries, its morphological complexity, and how much it resembles its English counterpart.
The scale is grouped into four zones: words a child would know, words a learner meets, words an experienced speaker uses, and words that stay in native-speaker territory. A short common word lands on the 100 HP floor; a rare, long, script-heavy word lands near 400.
What one correct answer is worth
Each game sets its own value, and MemDecks adds whatever the game reports. WordBase Quiz gives 3 points for a correct first pick and takes 1 away for each wrong pick in the same round. Word Type gives the number of letters you never had to reveal, reduced if you used a hint.
A 100 HP card therefore takes roughly 34 flawless WordBase Quiz rounds to reach 100%; a 400 HP card takes about four times as many. Difficulty is expressed as required repetitions, not as scheduling.
What this means in practice
Three consequences follow directly, and all three are intended.
- There is no penalty for a gap. A month away leaves your collection exactly as you left it.
- Progress is a record, not a prediction. 100% means the budgeted practice was done, not that recall is guaranteed.
- You control the mix. MemDecks will not stop you practising a card you already finished, and it will not force one you are avoiding.
The longer argument, with the reasoning behind each design choice, is in how MemDecks decides when to show a card again.