How does morale work.

[Polymorpher]

I didn't get to have notable bonuses to know.

[Elwin]

it incrreses/decreases critical chance atack and def of units

[Shadowdrake]

You can see the exact bonuses by opening up the stats screen of a unit and hovering the mouse over the smiley face below the unit portrait. It will tell you the percentage that your Attk/Def is increased/decreased, as well as your relative crit chance.