Let's imagine three systems where the two options would apply:-

System one (Where eligibility doesn't matter):-

  1. System adds all eligable users to a pool
  2. System picks X many random users from the list of eligible users
  3. System picks a random eligible game from those randomly selected eligible users and gives them the booster cards

System two (Where eligibility does matter):-

  1. System adds all user's eligible games to a pool
  2. Then picks a random game associated to a user from the pool X many times
  3. People who are eligible for multiple games are then in the pool/'hat'/etc... more times that people who are only eligible for one game.

System three (Where eligibility also does matter):-

  1. System goes through all GAMES and adds all users eligible for that game to a pool
  2. System picks a random player from the per-game pool

I know this is sort of hard to answer without access to the steam server source, but, hey, worth a shot of asking.

  • I always thought people who bought a game had a x% chance of getting a booster pack. Are you telling me now, that Steam simply picks x players at random to give booster packs to? Sounds like a huge pain to implement, to be honest.
    – Nolonar
    Oct 6, 2013 at 22:58
  • I have no idea, that's sort of why I'm asking.
    – Automatic
    Oct 6, 2013 at 23:16

2 Answers 2



As pointed out in the FAQ on the community cards and based on the research of the fellow steam users, the only factor that will increase your chances of getting a booster card drop is steam profile level. The bigger the number, the bigger the chances. An extract from the FAQ:

Once eligible, your Steam Level increases your rate of receiving a booster pack drop:

  • Level 10: +20% increase in your drop rate
  • Level 20: +40% increase in your drop rate
  • Level 30: +60% increase in your drop rate
  • Level 40: +80% increase in your drop rate
  • Level 50: +100% increase in your drop rate (i.e. the rate has doubled)
  • Etc.

Some Research

Here is a similar question asked on steam community.

I will give an extract from that discussion that serves our purpose (post):

Based on Valve comments on booster packs:

Having more eligible games = higher chance of getting a booster pack.

Not getting a booster pack in a while = higher chance of getting a booster.

Original answer:

Yes, over time you will end up with more boosters packs if you have more eligible games. It's all set up so that you are better off to have all your games on one account, instead of spreading them between accounts.


So this is generating some kind of confusion around this subject, since valve is not giving us something clear that we can rely on, and since nobody can run a test/experiment to prove something simply because the system cannot be reproduced or isolated in such way that it can lead to facts.

I think that the three system versions you came up with are purely theoretical and we cannot guess how the selection is being made. Consider the fact that it still gives booster to super low level users that are eligible also to super high level users that have greater chances.

The system

If it really matters the number of games you are eligible for than it could be very likely that the system is picking games randomly and then selects the users based on their chances due to steam level profile to give away the booster.

If it would pick the users first and the games after, the idea of having a bonus if you are eligible for more games becomes useless since it wouldn't rely on the game at all.

  • 1
    Don't use code markdown for quotes. Use the blockquote markdown instead.
    – 3ventic
    Oct 7, 2013 at 8:49
  • indeed i was kind of rushing and mixed them up, i will edit accordingly
    – Edeph
    Oct 7, 2013 at 10:04
  • Thanks a lot mate, really detailed answer, really wasn't expecting that!
    – Automatic
    Oct 8, 2013 at 8:25
  • @Automatic If you find my answer good enough don't forget to mark it as a correct answer so that the question will become closed.
    – Edeph
    Oct 8, 2013 at 11:30

System Four*

*(kind of Three combined with Two)

  1. The User creates badge for the Game using his cards.
  2. The Steam generates 1 booster pack for the Game.
  3. The Steam collects a pool of eligible users for the Game.
  4. Random user gets the prize

According to https://steamcommunity.com/tradingcards/faq/, emphasis is mine:

How can I get a booster pack? Once you have received all of your card drops, you become eligible for a booster pack, which is a set of 3 trading cards that may include both basic and foil cards. Booster packs are granted randomly to eligible users as more badges are crafted by members of the community. Make sure you log in to Steam each week to maintain eligibility.

All speculations (and some numbers) about probability of getting booster pack from https://gaming.stackexchange.com/a/133561/171544 also applies.

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