Steam Trading cards
When you play certain games on Steam, you can earn 'Trading Cards' as a collectible item. Those cards are placed into your Steam inventory.
If you collect a full 'set' of cards for a particular game, you can trade that set in for items for your profile, as well as a 'completion' badge. The items you can earn are as follows:
- a random game-specific emoticon (can be used in chat or discussions)
- a random game-specific profile background which can be used on your Steam Community profile
- a discount coupon for a different game or DLC
- 100XP towards your Steam profile level
Games might have different 'levels' of card sets, requiring you to collect the same set multiple times to fully max out your badge or earn more items.
Most games will drop half the total amount of cards. For example, Half-Life 2 has 8 cards in a set, so you will receive (max) 4 card drops. You can check how many drops you have remaining on your badges page. This basically means you won't be able to complete sets based purely on drops. This is where the Steam community steps in.
There are a couple of ways to build complete sets
- Trading - the simplest option to understand - you can initiate a trade with a friend or another Steam community member, asking for Steam Trading cards, and offering any Steam inventory item in return.
A good place to look for potential traders, is in the Steam community - especially forums and groups for that particular game. Another option is dedicated 'Steam Trading Card' groups, both on and off Steam.
- Community Market - straight cash for cards. A user can place a card they don't want up for sale on the community market. Most cards hover between the $0.01 and the $4.00 mark, depending on rarity. I'll be honest, this is where I got most of mine to complete the TF2 set, but that is a fairly popular game. Other games might have less cards around, driving up prices.
- Booster packs - another type of drop, you can earn 'booster packs' once you have received all of your card drops. These booster packs contain 3 trading cards, and are granted randomly as more badges are crafted by community members. To be considered eligible, you have to log into Steam at least once a week. Your Steam profile level also plays a role here:
- Level 10: +20% increase in your drop rate
- Level 20: +40%
- Level 30: +60%
- Level 40: +80%
- Level 50: +100% (i.e. the rate has doubled)
You can read more about Steam Trading Cards on Steam's FAQ