View Full Version : Converting BRP CoC to CoC Ruleset

January 4th, 2014, 13:30
Hi folks, I've been running 'Eternal Lies' as a Cuthulhu campaign with the BRP rules set and the CoC Extension. However, now the extension doesn't seem to work as it as well as it did, as it's not bringing the reference books across. Basically, is there any way for me to tweak and export the 'Eternal Lies' module (created for BRP) and the characters etc that I'm using in BRP for use in the updated CoC rules set?

If so, could someone kindly talk me through it? I would be eternally grateful. Or failing that, any other suggestions for a reasonable work around.

Many thanks.

Moon Wizard
January 4th, 2014, 20:53
There is no simple migration. The module could be edited to add "CallOfCthulhu" in the definition.xml file within the module; but some of the material would not work in CoC due to differing data structures (most notably NPCs). All of the story and image records should work without any issues.

A couple years ago, I converted the Masks of Nyarlathothep modules for CoC over to Savage Worlds for my game, but it involved a custom XML conversion tool I built where I used the Realms of Cthulhu expansion for SW to determine how to convert.


January 5th, 2014, 14:00
Hi Moon-Wizard,

Many thanks for the response. I followed your suggestion, and strangely it turned out to be the other way around. NPCs and images translated fine, but the story itself won't open.

It seems that even after renaming the module rules set "CallOfCthulhu" in the definitions xml. It still recognizes it as BRP. It appears in the module library, but any attempt to open one of the story tabs just results in script errors and fails to open.

For example:

Runtime Error: desktop: Unable to create window with invalid class (story : [email protected] Lies)

Appreciate your advice, however.

Moon Wizard
January 5th, 2014, 17:49
Ah, the story class is named "encounter" in the CoC ruleset. You might be able to do a search and replace on <class>story</class> to <class>encounter</class> in the db.xml file.


January 5th, 2014, 19:59
Many thanks, that did the trick.

The module story itself doesn't appear in the story tab on the table, but it can be opened from the module library, so it's certainly a workable solution.

Just to keep abreast of my options though, would you know how I would need to modify the script of the CoC extension (for BRP) to get it working again? The problem here is that it is no longer transferring the CoC reference books across to the BRP library. As a result I'm wondering if, since the CoC rule set update, the extension needs modifying to be effective. I only ask as I have invested such a considerable amount of time and work setting the CoC campaign up to run through BRP, and to change horses mid-stream now would still involve a lot of work that I'm reluctant to face at the moment.

Very good work on the rule set update by the way. If I wasn't mid-way through a major campaign, I would return to the CoC rule set now without hesitation. I fervently wish I'd just stayed with the CoC rule set to begin with!

In any case, your help has been greatly appreciated.

January 5th, 2014, 23:25
The problem here is that it is no longer transferring the CoC reference books across to the BRP library.
The CoC modules are tagged with the CallOfCthulhu ruleset name in the definition.xml file within the module with the following XML tag: <ruleset>CallOfCthulhu</ruleset>

You'd need to manually change the new FG 3.0 Call of Cthulhu modules to use whichever ruleset name is appropriate for BRP (sorry, I don't have the BRP ruleset so can't comment).

Or, if you made backup copies of your old modules before you upgraded to 3.0 you could copy those back into the modules folder and use those as I assume they were modified to allow the BRP ruleset to access them?

January 6th, 2014, 19:41
Many thanks Trenloe,

Job done. I really appreciate you taking the time to help.

The sense of community and guidance that I find here never fails to impress.