Forum

Until The Flowers of Algorab is officially released, I'm hoping to get my gaming group started using The Great Dark. Because they were on sale, I recently purchased the 'old' adventure/campaign books (for The Third Horizon), hoping that I could use them. I can't find The Third Horizon core rulebook anywhere. (This is probably why it was on sale.)

I have found conflicting information. The rules and procedures of the two systems are different, but I also read that the Mercy of the Icons campaign IS compatible. (I don't trust the AI summary which says "Yes, the Mercy of the Icons campaign is designed for the Coriolis: The Great Dark edition of the game.")

Has anyone here actually tried to use that campaign with The Great Dark?

I haven't tried it, but as you say the two systems are vastly different, and the icons play a much smaller role in the Great Dark setting.
I would either develop my own - I'm working on something, or try and find something else to convert into the Great Dark setting.
If you do like AI, then Claude is getting really good at understanding rule systems and develop ideas that are "on theme" and comply with the rules.
Maybe you can find some inspiration here:
https://www.drivethrurpg.com/en/product ... id=1752035