What's the world's hardest puzzle?

The Isis is the first puzzle in the Isis Adventure Series and players have to crack its combination to move on to the next stage in the series.
The Isis is the first puzzle in the Isis Adventure Series and players have to crack its combination to move on to the next stage in the series.
Image courtesy of Sonic Games

Action adventure movies often feature long treks full of mysterious clues before the hero or heroine finds a map, puzzle or locked box holding the keys to great wealth or for saving mankind from destruction. Indiana Jones, Lara Croft and others met their match in the form of puzzles and ciphers, some lying in wait and booby-trapped since ancient times. In real life, though, the puzzle is both the journey itself and the destination. Those who love a good puzzle do it for the exercise itself and the satisfaction of completing the challenge and finding a solution.

Many puzzles, whether math problems, word challenges or physical objects like 3-D puzzles and scrambled cubes, involve staying at home, one-on-one, man versus puzzle, while others combine an object and a quest into the physical world outside the game. The Isis Adventure, often dubbed the world's hardest game, starts as players find a way to open a round puzzle they can hold in their hands. Once inside, a key leads them on a search for a real hidden prize. It is, after all called an "adventure," so removing the puzzle itself from the box is only the beginning.

Some puzzles that came before The Isis Adventure have reputations among gamers as being just as difficult -- or even more difficult -- than Isis, one example being the book and treasure hunt known as "Masquerade," written and illustrated by Kit Williams. "Masquerade" was published in 1979 and sold more than 1 million copies. Readers studied the pictures and clues in the book and tried to identify real locations in England where they could go digging for actual buried treasure in the form of a gold bunny rabbit amulet. Two physicists found the bunny in 1982, winning the challenge and ending the hunt.

In 2005, Perplex City launched online and was similar to "Masquerade" in that it had a mystery to solve involving a complex story leading to a real location. The winner beat out 50,000 players from 92 countries and found the buried mystery cube, earning the $200,000 prize [sources: Amrich; BBC; Krotoski]. After these games were solved, "Masquerade" completely ended, while Perplex City was scheduled to release a new challenge, but as of 2011 it was still pending.

These alternate reality games (ARGs) combine a puzzle mystery with a complex storyline or ciphers and merge it into real locations and prizes for those who solve both parts -- the alternate reality and the, well, real reality. Tens of thousands of people worldwide have tried their hands at ARGs, either alone or in community with fellow players, and The Isis Adventure is well underway with a projected finish in year 2015.

But is it an ARG or something more or less puzzling? Are you game to find out more? See how The Isis Adventure is played, next.


Before looking at what The Isis Adventure is, let's take a look at what it's not. It's impossible to complete the entire adventure without the puzzles that go along with it. Unlike a classic math problem or word and logic mind game, each level of The Isis Adventure Series has an object to crack into. While there are options for subscribing to a membership and playing the game online without buying the puzzles, the ultimate winners and prizes come through both the puzzle "pieces" and the continuing online game after players crack the puzzles to reach the keys inside.

Another distinction is that the puzzles in the series are pricey by puzzle standards; the game isn't in the price range of the typical board game or puzzle ball, for example. Ranging from $145 to $5,600 for special edition pieces, the puzzles are handcrafted objects made from metals and alloys and boxed and sealed. If the seal is broken and the box is opened, the puzzle is non-returnable. Some players see this as a criticism but others appreciate that the objects are a true joy to hold and unravel and that once the puzzle itself is handled, the steps in solving it might be compromised.

There are a total of five puzzles in the adventure:

  • Isis -- A sphere: Open it "using your mind, not your strength" by following ancient symbols circling the ball and clues that point to the exact sequence of turns needed to release the first key.
  • Ramisis -- A pyramid: "Release the chamber within" by determining the exact alignment of the five layers of the pyramid to get to the key inside.
  • Copernisus -- Five rotating rings that "need to be aligned perfectly in order to release the key chamber through one of eight different key holes."
  • Isis IV -- Scheduled for release in 2012.
  • Isis V -- Scheduled for release in 2015.

Once they remove the puzzles from their packaging, each puzzle owner needs to register at the Sonic Games Limited/Isis Adventure Web site. Those who solve the Isis are "keepers" who move on to part two, the Ramisis. One word of caution from the Web site, though: "If you damage the Isis, the secret will be lost forever" [source: Sonic Games].

Playing the game starts with cracking the combination of the Isis puzzle, and with a band of ancient Egyptian hieroglyphics and cryptic clues, gamers have spent anywhere from a day to months before getting to the center of the alloy orb. Once inside, have they solved the puzzle?

See what mysteries await after the first ball is opened, next.

Solving the Isis Adventure

The Copernisis puzzle provides the third key required to help solve Isis V, which will be released in 2015.
The Copernisis puzzle provides the third key required to help solve Isis V, which will be released in 2015.
Image courtesy of Sonic Games

In addition to buying and solving each of the five puzzle objects, players need to then enter the code inside the puzzle on the Sonic Games Web site to continue the challenge and become eligible for prizes. What happens next is pretty mysterious until you open the puzzle and register, but continuing the game involves treasure hunts, hidden pyramids and keys -- both real and virtual -- and location-specific searches for cash and gold and silver coins valued at up to $750 or more in 2011. Of the 16,000 or so players from 18 different countries, there have been just 137 winners and 17 treasure hunts. Sonic Games promises that the players who are actually able to unlock the different Isis puzzles will find "an unbelievable and fascinating global pyramid treasure hunt that will take them to places they've never dreamed of going" [source: Sonic Games].

If you like to look at the last few pages of a book early into reading it or to cheat just a little when stumped on a riddle, you can do the same with the world's hardest puzzle. While the hints and tips won't come from the makers of the game, online videos, forums and helps pop up everywhere and with surprisingly respectful warnings that there are spoilers or giveaways that could help someone solve the puzzle and end the challenge.

When Rubik's Cubes were all the rage, it wasn't hard to find someone who had it figured out and could get the colored sides all lined up in seconds. Many of the solvers had numbered guides showing players how to turn the levels of the cube to fix an out-of-position colored square. Some players chose to take just a couple of clues and others memorized all the variations and enjoyed the game for the speed they had in "solving" it with the answers provided.

Anyone who plays the Isis Adventure can get hints and answers, though each puzzle is said to be entirely unique, with its own set of codes. But even if an owner of one of the puzzles gets the needed help and solves the puzzle, it is a different experience than the Rubik's Cube because once an Isis puzzle is opened, it can't be put back together and solved again and again. Some players lament the fact that they can't rebuild the puzzles and display them after solving because they are such well-crafted pieces.

People have been playing the Isis Adventure since 2006, and with the last piece expected in 2015 it will have had at least a good decade of avid playing around the globe. It is unique among puzzles for its mystery and its levels of play, both as an object and a quest, but is it truly the most difficult puzzle in the world? If you try it, let us know what you think, but no spoilers please. An Em Go! (Spoiler: That's an anagram for "Game on!")

For more puzzling information, see the next page.


How to Solve a Rubik's Cube

How to Solve a Rubik's Cube

How do you solve a Rubik's Cube? Learn the steps to solve a Rubik's Cube in this article from HowStuffWorks.

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More Great Links


  • Amrich, Dan. "Masquerade and the Mysteries of Kit Williams." BunnyEars.net. 2000. (July 29, 2011) http://bunnyears.net/kitwilliams/
  • BBC. "£100,000 Prize for Digital Hunter." Feb. 8, 2007. (July 27, 2011) http://news.bbc.co.uk/2/hi/technology/6344375.stm
  • BBC. "Masquerade: Kit Williams." 2011. (July 30, 2011) http://www.bbc.co.uk/dna/h2g2/alabaster/A533800
  • Encyclopaedia Britannica. "Rubik's Cube." 2011. (Aug. 1, 2011) http://www.britannica.com/EBchecked/topic/511992/Rubiks-Cube
  • Krotoski, Aleks. "Perplex Sorted." Guardian.co.uk. Feb. 12, 2007. (July 21, 2011) http://www.guardian.co.uk/technology/gamesblog/2007/feb/12/perplexsorted
  • Rubik's Official Web site. 2011. (Aug. 1, 2011) http://www.rubiks.com/
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  • Sonic Games Limited. "Isis." 2010. (July 27, 2011) http://www.isisadventure.co.uk/isis/index.php
  • Sonic Games Limited. "Ramisis." 2010. (July 27, 2011) http://www.isisadventure.co.uk/ramisis/index.php
  • Sonic Games Limited. "Copernisus Puzzle." 2010. (July 27, 2011) http://www.sonicgames-uk.com/section/copernisis-puzzle?name=copernisis_puzzle
  • Sonic Games Limited. "Isis IV." 2010. (July 27, 2011) http://www.isisadventure.co.uk/isis-iv/index.php