As per the latest Karnataka Recruitment of Gazetted Probationers (Appointment by Competitive Examinations) (Amendment) Rules, the KAS aspirants have to clear the 2-stage exam. The first stage is the Preliminary examination which comprises 2 papers with objective type questions.
The candidates who clear the Prelims become eligible for the Main stage of the exam. The Main stage of the KAS exam consists of a written examination and a personality test (interview). Hence, in effect, the KPSC KAS exam pattern is modeled quite closely on the lines of the UPSC IAS exam.