Super easy. You join a pass along with a list of others... A package (usually cigars) is mailed around to the participants who will take something from the package and replace with something else. So, you might take 3 cigars you've been wanting to try and replace with 3 of your favorites. You then box it back up and send to the next person. Person who started the pass gets the box last and has a whole new box of sticks (or whatever's).
sometimes there is a purpose for the pass for example my pass was for my 1 year anniversary and i have everyone signing a humidor as a remembrance of my time here.
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