Quote Originally Posted by Procrustes
I haven't been playing for long, but I get the feeling that many of the V&V's are pretty random.
After playing countless campaigns since the game came out I can tell you for sure the "weak attacker" vice and all vices and virtues associated with "attacker" or "defender" are not random.
You can easily test this for yourself.
Play a game where you control Scotland. Leave it with no garrison at all and no governor and highest taxes so it will rebel. It may take a few years between rebellions but its a for sure rebellion in Scotland if you do all this.
When the rebels appear look at what troops they get. Put together your most elite force BUT send less than 1/2 the total amount of troops the rebels have. At 1:2 odds when you win (which is quite easy against the low star generals the Scotts get) its 99.9% sure that your general will get the "skilled defender" virtue. Repeat this with same general it will become "expert defender". Go in at 1:4 odds and it will accelerate this process.

Instead you can choose not to defend and let the rebels have Scotland and instead invade it as the attacker. Same as stated above for odds and you will for sure get skilled attacker etc. instead of defender.

I suspect the "Weak Attacker" vice The_Emperor got was just plain bad luck of having the Hungarian allies join his attack which made his odds vs. the defenders so overwhelming that the AI demanded he have fewer losses even if he won. The fact his ally did little to help is beyond the AI's ability to judge I think. It probably uses simple math of odds vs. losses in each battle for that vice. I can only recall getting that vice a few times.