John Van Wagoner
Attacking causes a unit to be exhausted. that's how we played...thanks!
Defending does NOT cause a unit to be exhausted.
An exhausted unit cannot attack or defend.
So with that being said, if you attack with a unit, it will not be able to defend during an opponents turn. (Unless a card changes a units status).
Also, while a unit can only defend against one attacking unit per battle, if the defending unit survives, it is capable of defending against further battles that turn as long as it can stay alive.
Equipping armour and weapons means you flip 1 or both cards to the side you want. Doing so resets the abilities cool down just like any other ability use. Once it's ready again, you can use it if you like to change 1 or both cards again.