Cups
About Cups
Cups is the classic shell game · "follow the ball under the cup", played fairly. A small ball is shown under one of a row of cups for a moment, then every cup goes face-down and a sequence of quick adjacent swaps shuffles them around. When the shuffle stops you tap the cup you think the ball ended up under. Get it right and the round is up.
No trick. The game is fair. Unlike the street-corner version of the shell game, there's no sleight-of-hand here · the ball stays under the same cup for the whole round, and the answer is fully determined by the swap sequence. The cup you should tap is exactly the one the starting cup was swapped into, so a perfectly tracked round always wins. The skill is pure visual-spatial attention.
What it actually trains. Sustained visual tracking and what cognitive psychologists call multiple-object tracking · the ability to keep an attentional spotlight on a moving target through a cluttered field. The same skill underpins reading a busy intersection, following one conversation in a crowded room, or watching a particular player through a fast football play. Practising it as a game keeps the loop sharp.
Difficulty widens the row; level lengthens the shuffle. Easy rounds use three cups, a long initial reveal, and a slow shuffle. Harder rounds add cups (up to six), trim the time you get to see the starting ball, and pile on more swaps at higher labyrinth levels · so a single mistracked swap loses the round. Every shuffle is generated from the round seed, so a save code replays the exact same swaps.
Part of the PlayMemorize family of brain-training games. Runs entirely in your browser, works offline as a Progressive Web App.
FAQ
Q: Is there any trick · does the ball ever leave a cup?
No. The ball stays under the same cup for the whole round; only the cups move. The cup you should tap is exactly the one the starting cup was swapped into, so a perfectly tracked round always wins. Unlike a street-corner shell game, the game is fair.
Q: Is the shuffle the same for everyone?
Yes when handed the same seed. The number of cups, where the ball starts, every swap in the shuffle, and the timings are all derived from the round seed · the same save code reproduces the round move for move. Useful for shared challenges.
Q: How does difficulty change it?
Higher difficulty adds cups (three at the easiest, up to six) and shortens how long the ball is shown before the cover-up. Higher labyrinth levels add more swaps to the shuffle. A late-game round at hard difficulty might run a dozen swaps across six cups in a few seconds.
Q: What if I get distracted mid-shuffle?
Once you lose the cup, you're guessing. The classical recovery move is to fix on the visual position rather than the cup itself · track "the third from the left swapped with the second" rather than "the cup with the ball moved to position 2". The position-based mental note is more robust to brief attention lapses.
Q: Does it work in the Labyrinth and Polymath?
Yes. Cups ships as a labyrinth encounter and appears in the cross-game Polymath rotations when its reasoning pool is active.
Q: Does it work offline?
Yes. PlayMemorize is a Progressive Web App. Install once and Cups works without an internet connection.
