Candy Crush is officially a hard game, according to math

Developer King's match-three puzzler Candy Crush Saga is officially a difficult game, according to a new mathematical analysis of the title that places the game into a category of high-level computational problems.

The study, by University of New South Wales professor and group leader at computing research centre NICTA Toby Walsh, reveals Candy Crush belongs to the NP-hard class of math problems, one of the most difficult groups of problems to find solutions for.

Walsh studied Candy Crush with a method used previously to analyze classic Nintendo titles Super Mario Bros. and The Legend of Zelda, which showed these types of games are also NP-hard. Candy Crush is part of a NP-hard subset called NP-complete, a group of problems that become more complicated and difficult to solve as their size increases. Real-world tasks such as planning schedules and travel routes fall into this category of difficulty. Finding a way to solve smaller chunks of the problem at a time could help solve the entire puzzle — which is essentially Candy Crush's mechanic of matching individuals groups of three candy pieces.

Discovering Candy Crush's NP-hard status could explain the game's appeal; Walsh notes part of the title's "addictiveness may be that Candy Crush is a computationally hard puzzle to solve." Some researchers believe there won't ever be a way to efficiently solve NP-complete problems, but continued research — such as the millions of hours logged by Candy Crush players — could reveal some are easier to solve than others.

"It would be interesting to see if we can profit from the time humans spend solving Candy Crush problems," Walsh wrote. "Perhaps we can put this to even better use by hiding some practical NP-hard problems within these puzzles?"

Candy Crush developer King abandoned its efforts earlier this year to obtain trademark rights to the word "candy." King is currently planning to offer public stock soon, which it estimates could be worth between $21 and $24 a share and put the company at a $7 billion overall value.