There are two ways to get pins at the pin event - well, 3 if you count buying the event pins using your RSP.
1. Trading. This, of course, require that you have good pins to trade with other traders. Most of the people who are standing in line to play all the pin games are actually pretty flexible. If you find something of theirs that you want, they'll then look at what you have and see if you have something that they want. I've met very nice folks while doing this, and some even will trade with me for pins that they already have, just so I can have the pin that I want. But of course, there are also the "pin sharks". Most of them can be found at the pin trading section. Not all of them will take advantage of you, since we know quite a few from here that are extremely nice and accommodating. But with them, you really need to know your pins and their values just so you don't make a trade that you might regret later.
2. Pin games. This varies from one game to the other. In one game, you walk up to a board full of pins and you have a minute to pick, say 2 pins off the board in exchange for 2 of yours. The pins on the board can range from rack pins, limited edition pins, Artists Choice, and even rare cast lanyard pins. The boards are refreshed periodically throughout the day, so if they refresh it just before you get to it, you're in luck! In other games, you give them one pin, and you get to choose something at random, maybe pick a ball out of a bag that contains a pin. But be weary - the pin that you gave replaces the pin that you took out. This too gets refreshed every so often. That is why you need throw-away pins for these games.
Zz.
