Our free N-Back game is the position stream on its own at 2-back: press Space (or tap) when the lit square matches the one from two steps back.
It is how many turns back you compare with. In 2-back you compare each new square (and letter) with the one from two turns earlier; in 3-back, three turns earlier. You keep a rolling list of the last n items and drop the oldest every turn.
In our N-Back game, from the third turn on each turn has a 25% chance of being a forced repeat and otherwise picks any of the 9 squares, so about a third of turns are matches — roughly 6 in a 20-turn round. Accuracy is matches caught divided by matches shown; false alarms are counted separately.
Pressing a match key when there was no match. It is the error to cut first: only press when you are sure, because a missed match costs you one target while a habit of guessing piles up false alarms.
Each turn a square lights up in a 3×3 grid and a letter is spoken at the same time. Press the position key when the square is in the same place as n turns ago, and the audio key when the letter matches the one from n turns ago. Both can match at once, or neither. Start at 2-back.
Rehearse the last n letters under your breath while you watch the grid for position, instead of trying to picture both streams. Prioritise accuracy over speed — missing a match costs less than a false alarm — and only move up a level after two or three sessions at 80% or better.
When you score 80–85% or more on both position and audio at your current level across a couple of sessions. If you drop below about 50% after moving up, step back down — the task only trains you while it is hard but manageable.
Early studies reported gains on fluid-intelligence measures. Later, larger and better-controlled work has largely failed to replicate them, so treat the claim as unproven. Working memory improvement is more consistently demonstrated. What does improve reliably is your score on the n-back task itself.
Your n-back level usually climbs within two or three weeks of regular sessions. That is real improvement at the task; whether it carries over to everyday memory is much less certain, and the controlled studies that looked for broad benefits mostly found small or no effects.
If you're consistently scoring 85%+ at 2-back, advance to 3-back. The game should always feel challenging. If it's comfortable, you're not training effectively.
Yes. The browser version works on phones — tap the match button instead of pressing Space. The Mind Skills Arcade app also has an N-Back game that runs from 1-back to 3-back on the same 3×3 grid.
No — it is the position half of the task. Our N-Back game shows squares on a 3×3 grid and you press Space (or tap) when a square is in the same cell as two steps back. There is no spoken-letter stream, so it is a single visual 2-back. It is the right place to start: get comfortable with position matching before adding a second stream.