? How to play
There are two boxes, one on top and one below, each with its own rule.
- At the start, read both rules carefully — one for the top box, one for the bottom box.
- On each turn a letter-and-number combination appears inside one of the two boxes.
- Answer YES if the stimulus meets THAT box's rule, or NO if it doesn't.
- After several correct answers in a row, the rules disappear from the screen — but they stay the same, so you have to remember them.
- If you make a mistake, the rules show up again so you can review them before they hide once more.
