Prism Sort

About this game

Prism Sort is a ball sorting puzzle. The tubes come out of the shaker with ten colours jumbled four deep, and you put them back in order by pouring one tube onto another — a ball only ever lands on a ball of its own colour, or into a tube standing empty. Finish with every tube either empty or filled with a single colour and the board is done. What makes this version different is that it does its own arithmetic, out loud. Every board is dealt and then solved before you see it, so the par on the header is the genuine fewest moves the deal can be finished in, not a designer's guess at a fair target. Then it keeps solving. After every pour it re-derives the shortest finish from exactly where you now stand and shows it as Fewest, so the moment you spend a move you did not need to, you can see the number drift above par — and if a careless run has painted the board into a corner it cannot come back from, it says so instead of letting you shuffle balls for ten minutes finding out. Undo is free and reset is free, so that readout turns a wasted move into something you can learn from rather than something you have to live with. Four sizes run from four colours up to ten, difficulty coming from how much you have to hold in your head rather than from hidden traps, and a hint will search from your current position and show the single best pour from there. Every colour also carries its own quiet glyph, so ten shades stay tellable apart if colour alone is not enough. A fresh board arrives every day, easiest at the start of the week and hardest on Sunday, with a streak to keep and a par to chase.

Controls

Tap or click a tube to lift its top run of colour, then tap another tube to pour. Tap the same tube again to put it back.

Keyboard

• Number keys pick a tube, Arrow keys move the cursor and Space pours.
• Z undoes, H asks for a hint, R resets.

How to play

Tap a tube to pick up the run of matching colour sitting on top of it, then tap the tube you want to pour it into.

Pouring

• A pour is legal when the target is empty, or when the ball on top of it is the same colour and there is room.
• The whole run travels if it fits, and as much of it as fits otherwise.
• You have finished when every tube is either empty or holds four balls of one colour.

Par and Fewest

• Par is the proven fewest moves the deal can be finished in, worked out before you saw it.
• Fewest, beside it, is the shortest finish still available from where you are standing right now — while the two match you are on a perfect line, and when Fewest climbs you have spent a move you did not need.
• Undo and reset both cost nothing.

Read the full Prism Sort rules and strategy →