To Execute or not?

[bretwalda]

I'm playing a Viking campaign and have been choosing to execute the ringleaders after winning a battle. I am wondering what are the pros and cons for the 3 options: Execute them all - Execute the ringleaders - Release them all?

If my mind serves me well, 'ringleaders' is just no effect.

Execute them all: You will get butcher type vices (first is scant mercy that is actually helpful) People will fear you but morale and happiness suffers.

Release them all: You are merciful, but people after a while will less and less fear you.

Search for vices - that will explain.