The mount marks the man

[Zajuts149]

I was looking through the edu-file, and I have question about mounts. What are the differences game-wise between them? I know that fast pony makes the unit fast moving. What's the difference between pony and heavy horse? Heavy horse and barded horse?

And I found some answers in desc_mount-something. ponys have a mass of 1.25, Heavy horse 1.75, and other 2.00.