1. A condition adaptive-type control method for an internal combustion engine mounted on an automotive vehicle having a torque transmission mechanism, a brake pedal and an accelerator pedal, comprising the steps of: categorizing driver's intents and vehicle conditions, respectively, into a plurality of categories, and preparing different engine control methods for different combinations of said categories; detecting a driver's intent in accordance with the state of engagement or disengagement of said torque transmission mechanism, the angle of said brake pedal and the angle of said accelerator pedal; detecting said vehicle condition from the speed of said vehicle; and selecting one of said engine control methods in accordance with a combination of the categories to which said detected driver's intent and vehicle condition belong.