Logic?

What is the logic behind the games like age of empire ,tzar,commandos:Behind the call of duty
i mean how they adjust the each object's function?

Is hard to explain without visual aid, its the design of the games logic, go to your library and check out 'Game Architecture and Design' by 'Rollings and Morris'.

or you could just mean the AI, or Artifical Intelligence controling the actions of the "Objects" based on the game logic. in which case the book aove would still clear up the design and how things interact.