Screw Out: Bolt & Nuts

Empty bolts are your only workspace

Screw Out is a sorting puzzle wearing a hardware-store costume, and it follows the law of every good sort puzzle: the empty bolt is the most valuable thing on the board. You can only move a group of same-tone nuts onto a bolt that is empty or one whose top nut already matches, and no bolt holds more than four nuts. That empty bolt is the pivot you use to shuffle everything else, so filling it thoughtlessly, dumping a random tone onto it just to tidy one stack, is how you deadlock yourself with nuts you can no longer place anywhere. Before every pour, ask one question: after this move, where will my working space be? If the answer is nowhere, find a different move.

Think in whole groups

Clicking a bolt lifts the entire top run of matching nuts in one move, and fewer moves means a better score, so the aim is to unite each tone in as few pours as possible rather than shuffling one nut at a time.

• Scan first. Find the tone closest to being complete and drive your moves toward finishing it, which frees a whole bolt.
• Do not split a large matching group across two bolts if you can help it. You will pay extra moves reuniting it later.
• Pour onto the bolt that already holds the most of that tone, so a later move tops it off into a full single-tone stack.
• Count space before you pour. Three dark nuts will not fit on a bolt that already holds two, and half-fitting a group is how splits happen.
• Keep one bolt empty as long as you can, and give it up only for a move that opens two spaces in return.

A worked jam

Here is the standard three-bolt shuffle, worth learning by heart. Bolt A holds two dark nuts sitting on top of a light one. Bolt B holds a light nut on top. Bolt C is empty. The wrong move is dark straight onto C, because now both non-empty tops are light and your workspace is spent on a tone that was not stuck. The right sequence: lift the two darks onto C, which exposes A's light nut. Move that light onto B, joining its friends. Now A is empty and you have gained a fully open bolt while C carries a clean dark pair that future darks can join. Same three moves, completely different position. Nearly every hard level is this little rotation repeated: uncover the buried tone, deliver it to its family, and walk away with your workspace intact. When a run stalls anyway, work backward. Ask which single pour is blocking you, and whether a different order clears the jam. Most dead ends trace to one hasty move a few steps earlier, and the fix is usually to consolidate a tone you scattered. It also pays to read the depths before your first click. The nuts at the bottom of each bolt are the last ones you can touch, so a tone buried at the bottom of three different bolts is your real problem tone, and the level is secretly about excavating it. Aim your early pours at uncovering those deep nuts, and let the tones sitting conveniently on top wait their turn.

The sort-puzzle boom

These nuts-and-bolts puzzles are a spin on the water-sort and ball-sort games that flooded mobile app stores at the end of the 2010s, when half the phone-game charts seemed to be tubes of coloured liquid. The dressing changes (liquid, balls, hex nuts), but the puzzle underneath is identical: separate a jumble into single-tone stacks using limited space and a couple of legal-move rules. It is a genuinely old family of problems, cousin to classics like the Tower of Hanoi, where the whole difficulty also comes from a strict rule about what may stack on what. The reason the formula took over phones is the reason it works here: every level looks trivial, the first careless pour proves it is not, and solving one cleanly in a tight move count feels like tidying a messy drawer in record time. Finishing is easy. Finishing in few moves is the actual game.