Gameplay design patterns are semiformal interconnected descriptions features of gameplay. While most previous patterns have been identified through analyzing existing games, this paper proposed how patterns can be identified using theories as starting points. More specifically, we propose three different approaches to harvesting gameplay design patterns: 1) using theories as analysis foci, 2) distilling patterns from theories, and 3) using theories to understand the consequences of having or not having patterns present in a game design. The three approaches are presented together with examples of their use, and based upon this the concept of Theory Lenses as an analytical tool is introduced as a way of allowing theories independent of their research field to be applied to research on gameplay design.