Daily Review

Getting on the list: miss an item in any drill, on any level or mode, and it's in review — no threshold.
The session: most items replay right here — typed answer or tap-the-choice, exactly one pass, interleaved across topics. Items missed before the review system existed (or from modes that can't replay here) are listed separately with a link to their drill's Practice Missed.
The ladder: each clear pushes the item further out — 1 day, then 3 days, then 7. A correct answer at the 7-day check graduates it. Only one step per item per day counts.
Speed counts: a correct answer that takes more than 5 seconds holds its rung and returns tomorrow — the goal is automatic, not eventual.
Misses: missing an item drops it one step down the ladder (never back to the start). In the session you get one retry at the end — clearing the retry empties it from today's queue but doesn't climb.
Persistent items: after 5 total misses an item is pulled from rotation and flagged below — at that point it's usually a rule gap, not a speed gap. Read the drill's grammar capsule, replay the level it came from, then put it back in rotation.