The major ideas of chemistry, electrochemistry, and even microelectronics are associated with electronic ground states, or with states thermally accessible at modest temperatures. Photonics, and many realisations of quantum devices, require excited states. The energetic basis of life, photosynthesis, is possible only through excited state processes. Excited states are the basis of new processing methods for organic and inorganic systems. In wide gap materials, excited states and the processes they show are extraordinarily varied. Can they be controlled or exploited, rather than merely accessed in spectroscopy? When electronic excitation is used in materials modification, the ideas of charge localisation and energy localisation are central [1]. The basic processes are Energy transfer; Energy conversion; Energy control: Control of phase, which is more sutble (keeping a system on a specific energy surface is already challenging; keeping a system coherent in a way which can be exploited in quantum computing is far more difficult); and Dissipation, the antithesis of phase control. Length scales can span extreme miniaturisation in lithography or quantum dots, mesoscopic scales similar to optical wavelengths, and human scales. Timescales range even more widely, from femtosecond plasmon responses, through picoseconds for self-trapping or preplume ablation, to many years. These ranges identify different features in the “taming” of excited states. Some of these features are shown by simpler systems: F centres; the diamond vacancy; colossal magnetoresistance oxides, organics; and self-trapped excitons.