A sleeve and case assembly selectively encase and protect an electronic device such as a tablet computer or smart phone. Each of the sleeve and case assemblies is constructed from materials having high impact resistance or toughness qualities. The sleeve assemblies comprise two substantially identical half shells each of which are constructed from the impact-resistant material and are internally configured or contoured to together define a device-receiving volume operable to simultaneously prevent internal device shift or movement while providing the impact-resistant casing. The case assemblies each provide an impact resistant device-encircling material usable in combination with a device-receiving and positioning cradle to cooperably and selectively display an electronic device when in an open case configuration and protect the electronic device when in a closed case configuration. The posterior cradle and cover portions of each case assembly face in opposite directions when in the closed case configuration.