Pattern Lab — Hidden Rules, Evidence and Calibration
Twenty hard logic puzzles, one answer each and nothing to pick from: hidden machines, knights and knaves, coins and weighings, cryptarithms, Futoshikis, logic grids, nonograms and Mastermind safes. Free, no sign-up.
Pattern Lab is twenty hand-built logic problems, and every one of
them is open from the start — they are listed in the order they are meant to be
met, not the order you have to take them in. There are no options to choose
between: you build the answer on the board and the game marks it. Every puzzle has exactly one solution, and each one was
written against a solver that proves it — a logic puzzle with two answers
marks correct reasoning wrong, which is worse than no puzzle at all.
The first ten are a sealed machine whose rule you have five runs to work out;
knights and knaves, where one islander can only tell the truth and another can
only lie; twelve coins, three weighings and a fake that may be heavy or light;
the cryptarithm CROSS + ROADS = DANGER; a five by five Futoshiki with nothing
filled in; the bridge at night, crossed in seventeen minutes; a five-house logic
grid with eleven clues; eight bottles, three tasters and one day to find the
poisoned one; a ten by ten nonogram; and a five-dial safe cracked from four
failed attempts.
The second ten are the same forms asked harder: a box that returns a
difference of squares, five islanders instead of four, a Futoshiki with one
sign fewer, sixteen bottles against four tasters, CIPHER + CIPHER = SECRET,
five walkers at the bridge in twenty-nine minutes, a nonogram with no free
line in it, a four-house grid with four things to place in each, twenty coins
in four weighings, and a six-dial vault read off five failed attempts.
Three stars means solving it with no hint and no wrong answer, and a hint
costs one. Nothing is timed, because a clock rewards the person who already knew
the puzzle and punishes the one working it out. Progress is kept in your own
browser.
MultiVexo — Play. Guess. Discover. This page.