Innovation Rules or innovation evolution paths are described in this paper as a mechanism for identifying disruptive innovation opportunities. A generic structure of an Innovation Rule is first introduced followed by a discussion using specific instance of an Innovation Rule. The application of Innovation Rules for the discovery of disruptive innovation opportunities is presented next. Two methods that use Innovation Rules as the basis for identifying disruptive innovation opportunities are described next, one for market pull and the other one for technology push. A framework for dealing with Innovation Rules that represent both big and small disruptions is discussed next. Examples discussed in the paper should convince readers that Innovation Rules can be used effectively for the discovery of disruptive innovation opportunities.