Everyone loves a great logic puzzle. There’s absolute satisfaction in figuring out the solution, plus they’re excellent to keep you engrossed in something significant. The popular ones include Sudoku and Kakuro, while the lesser-known like Nonograms (cross numbers) and Bongard Problems are also quite loved.

However, these may not always be a beginner or pro-level games; some are evil and make you pull out your hair, sort of speak. So, here are five of those devilish logic puzzles that’ll test your solving skills and keep you busy for hours, even days together. It’s a classic 3D wooden puzzle that takes its name from the revolutionary naturalist Charles Darwin. To solve this one, the players take apart all the nine interlocking pieces of the puzzle and attempt to put them back to their original shape.

  1. Fill-a-Pix

A.K.A. nonograms or cross numbers, these are a mix of minesweeper and Sudoku puzzles based on a complex grid with a hidden pixel image. Invented by Trevor Truran, the solving rules of Fill-a-Pix require advanced techniques to create beautiful images. It’s easy to learn this game, and it’s also quite stimulating, absorbing, and addictive. The objective is to paint the squares around each clue, so the painted cells equal the clue’s value. Try solving this one:

(Puzzle Courtesy: ConceptisPuzzles)

  1. Kakuro

This crossword’s objective is to insert numbers 1 through 9 in each white cell without duplication, so the sum matches the clues. It has the elements of logic, basic math, Sudoku, and crosswords – all into one. The one mention here is said to be the world’s hardest. Try out yourself and see if it really is that tough:

(Puzzle Courtesy: ConceptisPuzzles)

  1. Bongard Problem

This puzzle was invented based on a simple rule – to spot the difference between the patterns or diagrams on the left and right sides. There’s always a common factor or attribute on one side which lacks on the other. So your aim is to find the rule that either side does not conform to. Try the one mentioned below:

(Puzzle Courtesy: Harry Foundalis)

  1. Sudoku

There would hardly be someone who doesn’t recognize this puzzle. But this one here is designed by Arto Inkala, who took around three months to make it the world’s hardest. On a scale from 1 to 5, this Sudoku gets an 11. It exhausts all your commonly known Sudoku solving techniques. Try it yourself:

(Puzzle Courtesy: Arto Inkala)

  1. Go Problem

This one’s a two-player abstract strategy board game. The objective is to surround more territory than your opponent’s. It’s 2,500 years ago Chinese invention, which is still popular. And like other paper-pen or board game, Go problems have also transitioned onto the webspace. Take a look at the one below – it’s considered the toughest one you’ll ever try. And let us tell you, this was last solved by a group of students taking them 1000 hours to conclude the game. Let’s see what it takes you to solve this Go problem:

(Puzzle Courtesy: Senseis)

That’s all for this blog.

This is our list of the most challenging puzzles ever. Let us know if you give these a try and how close did you get to success.