A while back, I worked on an online Flash version of the game show Don’t Forget the Lyrics. It’s a game show where contestants get up and sing along to some music until the music stops dead and they have to fill in the rest of the line. They have three lifelines (a la Who Wants to be a Millionaire) they can use: show the first three words, turn the question into a multiple-choice question, or get their pre-appointed friend to answer for them. The first two are easy to code up, the third not so much. We didn’t have the budget to record people singing the missing lyrics, so it had to be text-based. We thought of randomly selecting one of the multiple choice answers, but realized that people would probably feel cheated at being given a wrong answer. And it would be too easy to just always give them the right answer.
At some point, I came up with the idea of showing the player a scrambled version of the correct answer. That would leave it up to the player’s skill to get the correct answer from it, so it wasn’t a guaranteed success but would still seem fair. Then I had to come up with an algorithm for scrambling words that wasn’t too easy, but wasn’t too hard for anyone to solve in the time limit.