Quote Originally Posted by Creeper525
what part does mass play, Iv just now started hearing talk about this, how some units have 1, 1.2, 1.5,
It determines which unit is pushed back in a melee. A tall, heavy barbarian will be less easy to push back than a Roman town watch, for example, and both will be shoved aside by cavalry. Units with lower mass will lose against high mass units all other things being equal.