Hello. I want to design a turn based strategy game like Civilization two. Then, I want to make a real time based strategy like Age of Empires. How do I design a game? Do I write down unit attributes and stuff in a notebook? Do I create a huge 400 page storyline? Help me please. I am a very beginner.

If you are a "very beginner" I would suggest making a easier game like tetris first, then gradually increasing the size of the game. If Civ2 was easy to make, there would be thousands of civ2''s and aoe''s.

But if you do design such a game, I suggest you write down unit attributes, and any other info that describes the game and some sketches.