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APOCTHULHU System Reference Document

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This is the APOCTHULHU System Reference document. It contains all the open content from the APOCTHULHU RPG. We informally call this game engine the "Cthulhu Eternal" System (and other, non-Apocalypse versions of the same rules are published under that name). Whether you are a publisher or a gamer, you can use this under the terms of the Open Gaming License.

This is NOT the APOCTHULHU RPG Core Rulebook, which is a 330-page color book featuring extensive illustrations and game examples throughout.Neither is it the APOCTHULHU Quickstart, which is a briefer (but equally beautifully decorated) book which is a Pay-What-You-Want download.

This System Reference Document is, however, a perfectly playable (if unillustrated) version of the rules. If you're a player, we hope that you might be tempted to check out the full or Quickstart version of the game. If you're a game developer looking for a thoroughly open set of game mechanics based on a lineage of time-worn d100 games, we hope you'll consider reusing these rules for your own purposes.

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Customer avatar
Kai P September 26, 2021 5:57 pm UTC
Is there a license that allows 3rd-Party-Publishers (like me) to release material that is "Apocthulhu compatible" material?
Customer avatar
Chad B February 09, 2022 2:56 pm UTC
Kai -- the license is the last page. It's an OGL license which means as long as you follow the terms laid out you can use the text to produce your own material.
Customer avatar
Dean E February 09, 2022 11:06 pm UTC
What Chad said is correct -- for more info on what you can do with the SRD (basically anything, as long as you adhere to the simple instructions in the OGL license), see this posting on our blog:
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3.2 MB
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File Last Updated:
April 12, 2021
This title was added to our catalog on December 02, 2020.