I think this is the most efficient way to level up after you've hit light level 365.
ps. 3oc does not have a cooldown.
English
#Destiny
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You just got lucky there getting 2 exotic engrams to drop back to back. My group uses three of coins like they're going out of style and we never have exotics drop that frequent. I used about 20 three of coins today and only had 2 exotic engrams drop. Three of coins might not have a cool down, but I'm pretty sure that last year Bungie said that if you use them back to back it lowers the chance that an exotic will drop. No matter how you look at it RNG is all it is...