There is also the traditional medieval challenge being the doffing of a gauntlet and the picking it up of the opposer. More recently we have challenge caches pushing the competitive spirit of cachers to extreme levels.
The GCC December coin brings all these concepts together into a single coin, being depicted as a gauntleted hand seizing the geocaching signal lightning bolts on the one side with Challenge Accepted in text. the reverse being a knight in armor barring passage with the words Non Shall Pass above and Without True Heart below.
Drop your coin in your pocket and challenge your friends at the next event, who knows you may just earn a free drink.