The Rubicon model of behavioral phases distinguishes between four phases: weighing, planning, acting, and evaluating. Each phase instigates different mental states which are conducive to successfully completing the tasks each of them requires. This chapter first provides an overview of the previously studied effects of these mental states during the phases of weighing and planning on cognition and behavior. Subsequently, the chapter will discuss intention theory, differentiating between two types of intentions: goal intentions versus implementation intentions. Goal intentions represent states or standards an individual wishes to accomplish, while implementation intentions specify the required steps for the realization of the desired goal. The chapter discusses the processes that are initiated when people set these two kinds of intentions, as well as empirically documented effects on goal striving. The chapter closes with future perspectives for research on motivation and volition throughout the behavioral phases.