Intelligent Devices (インテリジェントデバイス Interijiento Debaisu) are Devices that incorporate sophisticated artificial intelligence in their programming, enabling them to have some degree of autonomy. Most Intelligent Devices seen in the series utilise the Midchildan or Modern Belkan magic system and speak English, though Steed shows that Japanese-speaking models are available to civilians. Intelligent Devices appear almost sentient, possessing their own thoughts and personalities. Subaru Nakajima has on several occasions spoken of her own Device, Mach Caliber as a friend or partner ("aibō") rather than a mere tool, which Mach Caliber reciprocates, calling Subaru her "buddy".