This trick requires the amount of gold needed, your
favorite hero, and units. First, go to the tavern and choose a
hero. You will notice the units below it. Garrison them and go
to battle. Retreat and return to the castle. You will notice your
hero is there. Hire the hero back, and you will again notice the
units that you started with. Garrison them again. This trick can
be done as many times as needed. Note: Upgrading them is an option,
but gold and the corrected castle is needed to do that.