Quote Originally Posted by hrvojej
The charge of cavalry against another cavalry unit head-on has no effect, as far as I can tell (in 1 on 1 battles at least). Nobody dies until the secondary weapons are drawn.

I think that the lances are too short so when the mounts come head to head the lances don't reach the rider(s) - and nothing happens. Since they also have the same mass, they cannot push into each other's formation either. I am not sure whether this is intentional, but it sure doesn't look like the tales of medieval jousting matches.
I was thinking of reporting this as a bug - has it been reported already? I stopped short though when I realised I was not sure if I had just been observing general's units. Their 2HPs might stop kills on impact.