How it works

Each row you type is a word, so the finished grid is solved. The maker then slides random rows and columns, 3 moves on Easy, 4 on Medium, 5 on Hard, never undoing the move it just made, and checks the result is not still all words. A solver then tries every route from the scrambled grid and finds the fewest moves back to rows of common words. That number is par, and it is proven, not guessed.

Par is often lower than the number of scrambling moves, because two random slides can cancel out or open a shortcut to other words. The maker tries up to 30 scrambles and keeps one whose par is close to the difficulty you chose. On 3x3, Hard usually gives par 4, because small grids have so many short ways back; 4x4 Hard usually gives par 5.

Which words work

Rows must be common or everyday English words from the site’s list (about 575 three-letter and 2,300 four-letter words), all different, letters only. A word that is in the list but rare, such as QAT, is turned down so your friend’s par is reachable with words people know. A few crude words are turned down too.

Your friend does not have to land on your exact words: any rows that all read as listed words count as solved, so they may beat your par with a route you did not see.

Tips for a good puzzle

• Words that share letters (CAT, ACT, TAN) make grids where many slides look promising, which is harder than it sounds.
• On 4x4, one column slide changes a letter in every row at once, so Medium already feels hard.
• Hidden messages work: four words that make a sentence (SEND MORE CAKE SOON) turn into a puzzle and a note.

The link and your privacy

The whole puzzle travels inside the link, after the # sign: the size, the scrambled letters, par, the par route and a check code. Nothing is uploaded or stored on a server, and the part after # is never sent to us when the page loads. A link that has been cut short or edited fails the check and opens this maker with a note.

The scrambled letters are visible in the link, so it is a game for friends, not a secret code. The only things counted are anonymous tallies of puzzles made, shared and solved, with no words attached.

Want a puzzle made for you? Play today’s daily Typeslide or the 177 levels.