Einstein Enigmas (Puzzleship)

Einstein Enigmas belongs to the Zebra Puzzle family but changes how it is played and what the clues say. Each clue either puts an item in a numbered house or says two items share a house, and many do it in the negative, ruling a house out. There are no left, right or next-to clues at all.

Clues check themselves. A satisfied clue strikes itself out and a broken one turns red, so an early slip cannot quietly ruin a long solve. The puzzles grow further than their siblings, from four houses and four attributes to six houses and eight, with clue lists running from about ten to fifty or more. Colour is always one attribute; the rest change daily, from instruments to seafood.

Puzzleship publishes six enigmas of Einstein Enigmas a day, graded from very easy to ultra hard. Each day's enigmas are numbered and dated, the same for every player, and the page says they appear at midnight in your own time zone, though the day's set actually goes live at 13:00 UTC; earlier days stay playable in the archive. The site is free with ads, and a premium plan removes them.