I think that it could be cool for players to be able to transfer coins to one another. A way to do this is if each player had something like a Transfer Code, and they could send this code to a friend. The friend would then enter the code into a spot where it will say something like Send _______ Coins To (Transfer Code Here). Other ways could be by username, but this could be easy for people to intercept the coins, by switching names. Once guilds are added, the guild might be the way to send coins, kind of like a perk to being in the guild, which will encourage players to join guilds and be active.
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