Did you ever notice a big mean hero approaching to your key city and you wish you had 400 more gold to upgrade the city level? Or you are just 10 gold short of buying that Red Dragon you always dreamed of?
Now you can.
With the new borrowing feature you can borrow gold and get to negative for one turn. You have to pay back the loan with %25 interest, but it is surely better than loosing a key city. And that Red Dragon you always dream of? He will surely pay off.