What a great time waster. No skill needed. You can even level up enough to sit there and let your computer dudes fight and collect gold for you. But, that's not really necessary because...
It's kind of a trip... It keeps going, if you will, while you're not playing it. I came back to it after a few hours and it gave me a shit-ton in free gold. Apparently it's based on time though because I closed it and re-opned it and it said I was gone for 20 seconds and it gave me 600k.
This is probably not something new, but it's new to me. lol
I guess that explains the 'idle' Champions part . It is already a free-to-play game so I'm not sure what exactly we got - I guess the 'Epic Champions of Renown Pack'. Looks like must install and login to get the Epic pack though.