Fight solving rules

Lot of people ask me how does the game work internaly. What are the rules for solving a fight, how do I compute the losts etc etc. Therefore, I will try to post regulary with some infos, tips…
Please, excuse my poor english, this is not my native tongue,
I do my best :$

Today, I’m going to explain how do I choose who win a fight

To determine which player will win a fight the game operates in three steps :
- first, it computes the attacker points. Which is the number of attacker * the attacker factor (which is specific to each empire)
- second, it computes the defender points. Which is mainly the main formula plus some other factors (terrain, if country is fortified …)
- then, a ratio is computed to give a percentage of win for the attacker.

For instance, if the attacker has 100 points and the defender has 50 points, the attacker have 100/(100+50) of chance to win. Which is a 66% of chance to win.
A dice from 0 to 99 is rolled. If the result is below 66, the attacker win.

After this first phase, a second one take place to determine the losts. This will be explained in another post.