Here is a free PDF on the history of challenge coins, https://www.google.com/search?q=UAHCC-v0.99&ie=utf-8&oe=utf-8 In the last few years there have an increase in first res ponder unit coins and fantasy coins to truly be a challenge coin there must be a rank on it. Either military or in the government officials ie president etc. Since there are few ranks in the police and fire depts. It wouldn't seem tyhat the challenge drinking game would work to well.
Here is a link to one of the large producers of specialty coins for scouts, nurses, and just about anybody that will pay the cost of getting them made up. https://store.nwtmint.com/index.html
Those seem to be generic and mass-produced. The ones I've seen/have are usually custom made for the unit, organization or specific event.
They were carried in the pocket of military people with the coins and used in a drinking came of who buys the round of drinks. The lost ranked coin buys the round. hence challenge coins. most people other than collectors are discerning enough to make a decision between, medals, coins, tokens jewelry etc. If its round and looks like money it is money. Check out the free PDF download on them that starts this thread. Post #1
No idea why they post side ways. My orientation is correct when I look at them. Oh well here are some of my challenge coins.
This is the challenge coin from MajGen Charles Bolden, USMC (the Astronaut) when he was the Deputy Commander of United States Forces, Japan. GREAT person to work for!!!