how do you earn trading card things for l4d2?

[General SnuSnu]

im trying to get em all

[Visi]

The same way in any other game. You earn the cards just by being in the game. You can just sit at the main menu if you want. You will not, however, be able to earn them all just by playing. You'll only be able to earn about half of the cards necessary to craft the badge, which if I remember correctly is 4. If you want the others, you'll either have to find other people to trade with, or buy them off the community market.
Also, there are 5 levels to the badge, and a foil badge as well that uses the foil cards. So if you want everything, you'll need 5 sets of the normal cards and 1 set of foil cards.

[Ruke (Soreasan)]

Yeah, when you buy the game you get access to half the card drops.

Then you play the game, and while you're playing it the cards will be put into your inventory from time to time until you run out of card drops available.

After that, you either have to trade or buy the other half of the cards to complete your set. The trading fourms is a good place.

[General SnuSnu]

ohh i see okay thanks guys