Roberta had heard that there were some Adventure-style games available for the Apple. Roberta bought some at a computer store in nearby Northridge in the San Fernando Valley, but she found them too easy. She wanted her newly awakened imagination to be as taxed and teased as it was before. She began sketching out an adventure game of her own.
She started by writing out a story about a 'mystery house,' and things that happened in it. The story had much to do with Agatha Christie's Ten Little Indians — another inspiration was the board game 'Clue.' Instead of just finding treasures as in Adventure, this game would have you do some detective work. Roberta mapped out the story just as she mapped out an adventure game when she played it. Along the way, she devised puzzles, character traits, events, and landmarks. After a couple of weeks she had a stack of papers with maps and dilemmas and plot turns and twists and she flopped it down in front of Ken and said, “Look what I did!”
Ken told Roberta that her little stack of papers was very nice and she should run along and finish it. No one really wanted to use a personal computer as a game machine — they were for engineers who wanted to figure out how to design circuits or solve triple-x exponential equations.
— Hackers: Heroes of the Computer Revolution, Steven Levy