Gold and Elixir
While you play and lay siege to enemy fortresses, you'll earn Gold and Elixir as your rewards. Funny thing is that even if you win a battle, all of your deployed troops are lost in the process. This doesn't make much sense of course and it forces you to spend Elixir to train replacements before you can once again head into battle.
If you're winning a battle and haven't deployed all of your troops, don't and keep from having to train replacements when you return home. However, if you do and they survive the battle, all is not lost. They will be converted into elixir you can use to train replacements.

Embark on an inspiring mission of human connection beyond the UCA. Sam — with companions by his side — sets out on a new journey to save humanity from extinction. Join them as they traverse a world beset by otherworldly enemies, obstacles and a haunting question: should we have connected?