Thanks for your posts! and sorry for answering so late (exams season in the university). Well I read the AI Tutorial WILL suggested, and I found it very interesting (thought it will take me years to implement it in my game ). The A* Algorithm seems pretty interesting too!

Well I guess you could give me more ideas if I explain more about the battle engine:

The game is turn based. The robot with the greater speed acts first, and can move, use technique or do nothing. Every technique has a range, and an explosion range. Teh techniques also have effects on his target (lower defense, etc...).

That are the basis of the game. Any other idea will make it!