Three-dimensional N=2 supergravity theories: From superspace to components

For general off-shell N = 2 supergravity-matter systems in three spacetime dimensions, a formalism is developed to reduce the corresponding actions from superspace to components. The component actions are explicitly computed in the cases of type I and type II minimal supergravity formulations. We describe the models for topologically massive supergravity which correspond to all the known off-shell formulations for three-dimensional N = 2 supergravity. We also present a universal setting to construct supersymmetric backgrounds associated with these off-shell supergravities.