Augmented reality presents a rich variety of possibilities for entertainment and gaming, both indoors and outdoors, and especially when mobile.  In this talk, I will discuss some of the themes underlying our augmented reality research, as applied to entertainment, ranging from first-person shooters to gentler pursuits:

• Ubiquity, exemplified by the ability to interweave content seamlessly and pervasively with our environment, in ways that are sensitive to our physical and virtual context.
• Heterogeneity, in which we benefit from the complementary advantages of a diverse set of interaction devices and displays.
• Collaboration, both symmetric among equals, and asymmetric among participants with differing computational abilities, devices, and goals. 
• Authoring, emphasizing the need for effective tools, and the potential for on-the-fly changes. 
• And, finally,...Simplicity.