License of Advent/Adventure and Colossal Cave Adventure


I will ask you if the IF Advent / Adventure or maybe Colossal Cave Adventure is in Public Domain?
According to the Wikipedia mention page this it the case see:

But I don’t know really why this is licensed as a Public Domain game cause the game is released under 50 years old.

So what is the reality about this game and license…Can I use/modify it for commercial use?

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It’s generally been treated as being in the public domain, but as far as I know there’s no actual legal basis behind that. It comes from an era where people would freely extend and reuse and modify code, both commercially and non-commercially, without much concern about copyright, and I don’t think the original authors ever said anything on the topic (beyond being happy it was getting expanded).

People have used and modified the original code for commercial purposes plenty of times, without any real objection, so I doubt anyone would object now if you did the same.


I would say it’s generally been treated as if it were open source, from an era before formal open-source licenses. Not really the same as public domain.

A few years ago someone went to the trouble of getting permission to release a version with a formal open-source license: Eric S. Raymond / open-adventure · GitLab

In practice, same as it always was.

People have used and modified the original code for commercial purposes plenty of times, without any real objection, so I doubt anyone would object now if you did the same.

That is true. Bill Gates did it in 1981, in fact.


Fair; I’m paraphrasing Graham Nelson there.

The Level 9 games began with a good port of `Adventure’ (which was generally considered at the time, and ever since, to be in the public domain, on what legal grounds it’s hard to see) and then two sequels in similar style.

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Public domain means that that either (1) the author has relinquished any exclusive copyright protection on the work, (2) there was no basis for such protection in the first place, or (3) protection has expired. In the case of Adventure, I think the legal argument would be that Crowther & Woods have de facto done #1 by their tacit (and at times dicit) approval of all the various derivative works that have come since [1]. So I think there is a legitimate legal case for it being public domain, not just open source, but obviously the issue is muddy enough for people like ERS to have gone to the trouble of getting explicit permission for a BSD-licensed release.

But now that that has been done: yes, you can use/modify it for commercial use. (see relevant BSD license)

[1] The exception to this is Woods’ 430-point version, which does include a statement asserting copyright over that version at least.


The irony is thick there.

Untrue. Although published by Microsoft, Bill Gates didn’t write it. He was busy coding DONKEY.BAS!

Written by Gordon Letwin, of SOFTWIN, Associates.

From Byte Magazine, as referenced on Wikipedia.


I wonder if he also wrote GORILLA.BAS as well. Because that was always included too.

For those who care about such things, this is the 430 point version not the more well known (I think!) 350 point version.

And for those who have said that it’s impossible to beat it with a perfect score, it turns out that it is possible. My proposed solution accidentally exploited a bug to save a move, so I failed. But I did uncover some bugs along the way that has since been fixed, and Ryan Sarson has found ways to improve on my attempt. So I’m ok with that. :grinning: