Complex sentence: Gilbert and Winnick created "Maniac Mansion" s basic structure and story prior to programming; its earliest version was a simple paper-and-pencil board game, which the mansion's floor plan served as the game board, and cards represented events and characters.
Split into simpler sentences: Gilbert and Winnick created "Maniac Mansion" s basic structure and story prior to programming; its earliest version was a simple board game, which was playable on paper. The mansion's floor plan served as the game board, and cards represented events and characters.