Crabs Adjust Humidity is, as its makers describe it, "a crappy little third-party, unofficial, unauthorized expansion card set" for the wildly-popular game known as Cards Against Humanity.

Personally, I love the idea. I don't have the expansions myself yet, but I think it's great that people can create things like this to even further expand a game that I thoroughly enjoy. (Further, that is, beyond the existing, official 6 major expansions and dozen or so minor booster packs.)

However, I am also wondering a bit as to how they can legally do what they're doing.

Presumably, this is facilitated by the fact that Cards Against Humanity uses an unusually-permissive license for a commercially-sold product of its sort. The game, and all official expansions, are under a Creative Commons license which allows other people to do a number of things that they wouldn't be able to do under the typical copyright licenses attached other works.

In particular, without needing to pay royalties or obtain special permission, other people can:

  • Copy and redistribute Cards Against Humanity as-is.
  • Make and distribute derivative works that are based upon, and may even partially or fully include, Cards Against Humanity.

However, the particular license used for Cards Against Humanity is CC BY-NC-SA 2.0. This puts the following restrictions upon sharing and re-use of Cards Against Humanity:

  • Attribution (BY): Appropriate credit must be given to Cards Against Humanity LLC, and changes from the original work must be noted. This should not imply any endorsement by Cards Against Humanity LLC.

  • Non-Commercial (NC): Any copies of Cards Against Humanity, or derivative works, are not to be used for commercial purposes (e.g.: sold) without permission of Cards Against Humanity LLC.

  • Share Alike (SA): All copies of Cards Against Humanity, or derivative works, must use the CC BY-NC-SA license or another Compatible License.

Crabs Adjust Humidity clearly meets the BY requirement. They mention several times over on the site that their expansions are not official and they are in no way affiliated with Cards Against Humanity LLC. A notice on their website even specifically states that it is not the Cards Against Humanity website, provides a link to the official Cards Against Humanity site, and encourages people to "Go there and buy it now. We'll wait. Get all of the official expansions, too. They rock.".

The NC requirement is where they most obviously appear to fall short. Crabs Adjust Humidity is being sold, both directly from their own website as well as through other vendors. (Personally, I first discovered the products by seeing them on a shelf at my favorite local gaming store.) Each individual expansion (each containing 112 cards) costs $14 USD, with a boxed set of all 5 for $50 USD ($10 per expansion/$4 off each pack/$20 off the set).

For comparison, Cards Against Humanity sells their main game (550 cards) for $25, major expansions (100 cards each) for $10 each, and smaller expansions for varying prices. There is no official boxed set for Cards Against Humanity. (The Bigger, Blacker Box is - mostly - just a box.)

So, Crabs Adjust Humidity expansions are being sold at about a 25% higher per-card cost than the official major expansions. When you compare the boxed set of Crabs Adjust Humidity to the official main game, the former has a nearly-double per-card price. (Arguably, this isn't an "apples-to-apples" comparison.* But it was a lot simpler than trying to differentiate costs between Black Cards and White Cards.)

Crabs Adjust Humidity also seems to fall afoul of the SA requirement, as the product (as seen on their Counterfeit Crabs page) and the website have the standard "copyright ... All Rights Reserved" notices. Thus Crabs Adjust Humidity cannot be handled per CC BY-NC-SA, as the license on Cards Against Humanity would seem to require.

Of course, infringement upon copyright (whether actual or simply perceived) tends to not carry consequences unless the copyright holder chooses to pursue them. However, it seems that the creators of Crabs Adjust Humidity (and, as I've discovered while writing this post, about a half-dozen other companies) have chosen to make and publicly sell these works in seeming violation of the CC BY-NC-SA license without much fear of such recourse.

Is this all really legally defensible, or are these products only surviving because Cards Against Humanity LLC has not yet chosen to take action against them?

*Pun not originally intended, but now it totally is.

  • 1
    Do you categorically know the crabs distributor did not obtain "permission of Cards Against Humanity LLC."?
    – user662852
    Apr 23, 2016 at 12:17
  • NC could be argued to mean they do not get a profit... Maybe those prices simply cover production costs.
    – Viktor
    Apr 23, 2016 at 14:00
  • @user662852 Strictly, no. Though their website publicly and completely disavows any affiliation with or authorization from Cards Against Humanity LLC, I suppose it is possible that there does in fact exist some deal between them. However, I have also seen at least one article around the web where a creator specifically said adaptations like Crabs Adjust Humidity "irks" them.
    – Iszi
    Apr 23, 2016 at 18:11
  • @Viktor At 125%-200% of the regular product's price? Seems a bit off to me. Even if so, there's still the SA issue.
    – Iszi
    Apr 23, 2016 at 18:12
  • 2
    In other news, the Crabs site has vanished. Which might allow us to infer something. Nov 12, 2022 at 8:32

3 Answers 3


The "Crabs" game can be legal if it is seen as a form of parody. That is one of the forms of "fair use" that allows copying (within limits). This is to allow the use of limited amounts of copying for critical or "mocking" pieces, which are considered a form of free speech.

Two other issues come into play under "fair use." The first is whether or not this is "commercial" (yes) or non-commercial (e.g educational) use. That is mildly negative for "Crabs" but by no means dispositive. The second is the likely market impact, whether the new use tends to compete with the old use in its "home" market, or whether it is likely to open a new market of a very different, perhaps "opposite" audience that might later buy the original as a "crossover."

The "Crabs" game seems to address the "green" or at least "pro animal" (PETA) market. If the defendant can show that the "Cards" market addresses e..g., your "inner Nazi," making it "opposite," that would be ideal. It would be less convincing if "Cards" were addressing e.g. human rights, because that might be seen to overlap with the green market in terms of social conscience.


I don't think we have any way of knowing how or why the crabs haven't been cooked. This article is critical of the NC license. The relevant language in the license says:

NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation. For purposes of this Public License, the exchange of the Licensed Material for other material subject to Copyright and Similar Rights by digital file-sharing or similar means is NonCommercial provided there is no payment of monetary compensation in connection with the exchange.

A literal reading of the license terms would mean that you cannot take a journal article (for example) to a copy shop to make a copy, unless the shop makes all copies of NC materials for free. The terms do not say anything about profit: it requires there to be no payment of monetary compensation in connection with the exchange.

It is not clear to me that there is any potential copyright issue here. You can't copyright the idea of a smart-ass card game, and it is not evident that there is any actual copying of the original material. They do not seem to be actually selling copies of the original cards, so no clear issue of infringement.

  • 2
    I would say that the copy shop example wouldn't count because the copy shop is making profit off of your use of the copy machine to make the copies. The content of the copy is not what they are selling, but the service of making the copies for you for your own use.
    – hszmv
    May 17, 2023 at 17:08

It seems they did get into legal trouble with Cards Against Humanity, relating to the trademark, from this hearing from October 9, 2018: https://ttabvue.uspto.gov/ttabvue/ttabvue-91225576-OPP-66.pdf

  • 2
    Link-only answers tend to be downvoted and/or deleted, so you may wish to add some relevant extracts.
    – user35069
    Nov 12, 2022 at 8:20
  • 1
    ... especially when they're behind an impenetrable paywall:(
    – user35069
    Nov 12, 2022 at 9:01
  • @Rick I know nothing about law and came across this recently when I was also interested how Crabs Adjust Humidity was able to sell their products. Seeing as the last activity on this post is 6+ years ago, I figured it’s useful info. I’m not about to summarize something I know little about though, if you would like to expand on it for an answer feel free. Adding a different link as well. Downvote or remove if you wish this is likely the first and last time I’ll be on this exchange
    – JCKE
    Nov 13, 2022 at 21:21
  • OK, thanks for taking time to improve it with your new link which is accessible to all. And I have no intention to downvote or delete this post - I was just forewarning you in case others did.
    – user35069
    Nov 13, 2022 at 21:43
  • 1
    that filing is just that they can't have the trademark. that's no lawsuit.
    – Trish
    Nov 13, 2022 at 23:19

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