Keep an eye out for pretty much any "giveaway" games. Stuff like Pixel Puzzles (there's like a dozen varients of that game so they seem to give away on rotation) or games which are on greenlight as "vote for us for free copy of game", if you're willing to stoop to that level of unscrupulous.

There's groups dedicated to giving notice about such giveaways. Just search "Giveaway" in the group listings and you'll probably find 20 in as many seconds.

True "Free games" like TF2 won't give you cards efficiently unless you're the sort of person who buys TF2 keys (or whatever the game in question's equivalent is) in bulk, since it's every $15-$20 USD that you get a free card as a bonus. With each card worth about 9 cents in USD, you can see why this doesn't work nicely.

https://www.reddit.com/r/FreeGameFindings/new/

引用自 Hamstersex：

https://www.reddit.com/r/FreeGameFindings/new/

Anyway to find out if they hAve trading cards?

引用自 blakeblood9YoutubeYEE HAW!：

引用自 Hamstersex：

https://www.reddit.com/r/FreeGameFindings/new/

Anyway to find out if they hAve trading cards?

Check their steam page. There's a tag for cards. It should be on the right, alongside stuff like "Controller support".