Codebreaker (Puzzleship)

You never make trial guesses. All the evidence is on screen from the start: a set of attempts and their scores, with nothing saying which digit earned which peg. You compare rows against each other to work out the code, then type it into the bottom row, which only unlocks when every digit is right. Digits may repeat.

Rows at the extremes are the place to start: a row with no pegs removes all its digits, and a row with every slot pegged gives the whole digit set. Rows that differ in one or two places are worth comparing, since the change in score comes from that difference alone. Harder puzzles show more rows because each says less.

Puzzleship publishes six codes of Codebreaker a day, graded from very easy to ultra hard. Each day's codes are numbered and dated, the same for every player, and go up at 13:00 UTC, whatever the page's "00:00 your time" line says; earlier days stay playable in the archive. The very easy code has three digits and four rows; the ultra hard one has seven digits and a long stack of rows. The site is free with ads, and a premium plan removes them.

Solving a code opens a short congratulations card with a day streak, which is kept in the browser unless you sign in. On a phone the board fits in one column and the difficulty tabs become a drop-down list.