How do you earn courage medals?

Courage medals can be earned in a few ways. They are a random drop from attacking normal zombies in the world. However when attacking zombies of each level for the first time you will get a fixed number of medals as a reward. eg 30 medals.This is a one off reward though.

The best way to get regular amounts of courage medals though is via events. They are also given out in certain reward boxes for the Clash of Zones daily events. the higher your level and the more reward boxes you can claim each day the more you will get.

Courage medals are an occasional reward from attacking zombies.

As far as I can tell killing rebels or zombies is the only way. The chance to get em is waaaay to low though. Especially considering you need them for tech and hero recruitment.