Unit Ability levels???

what are unit ability levels for? i understand hero abiltiy levels, but how do you get to the next level of a unit abiility, do you make requirements, and as those are met, the ability will increase in level, or you just use the set level of ability function? o_O

When you change the max. ability level of a unit ability you get more text fields, therefore you can add a condition for each level if you want to.
Unit abilities have levels so you can make things like:
- Using the normal attack boost and armor boost abilities, but with a lot more levels
- Give some levels to abilities like bloodlust to they are more powerful at each level you research them
- Use ability levels as a "counter" when triggering
etc.

Think of things like weapon damage upgrades in melee, it is that sort of thing. You're simply reseraching something to "level up" the unit's ability.

all right, any other opinions? what if they have no requirements will it automatically go to the last level?

any unit ability start on lvl 1 until you upgrade it whit techs or triggers. its verry useful for dummy units used in triggered spells

but what if it has no requirements????

It won't upgrade automatically. Requirements or not, you need to either pay its price and wait for it or trigger it to level up.