Rubics Cube Color/Letter Lock
A regular chain lock with a Rubics Cube and Letters on each square of the Cube. You spell the word or words you want, line up the color or colors you have preset then unlock the lock. A never ending amount of simple or complex choices!
A child would want a gree line saying "CAT" in the middle of the cube for instance and it would only have to be on one side. For Adults you cound make the Rubics Cube have more Squares to spell out longer, more complicated words on all sides spelt at angles for more safety.
Reward: A lock with the "Entire, English" Alphabet!