Abstract
Serious design of digital games is aiming at impact. Humans players may be affected by experiences in virtual worlds. Game designers anticipate potential experiences. Storyboarding is the technology of setting up conditions of future experience. Structural properties of storyboards correlate with potential human player experience. Those properties are named patterns. What shows when game play unfolds are instances of patterns. Patterns are formal concepts and relating patterns and instances requires formal methods. But how to arrive at new creative ideas? Patterns make design ideas explicit. The potential opportunities of modifying a certain pattern or of replacing it by another one determine ways of introducing novel variations of game play and related players' experiences-an issue of creative game design.