A downloadable SRD

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Caltrop Core EX is a spin-off of the original Caltrop Core system, born naturally out of my own attempts at seeing how robust a TTRPG I could make with it. In classic Caltrop Core, you roll your dice pool and use the highest result. Any other results are discarded. But after watching Spencer Campbell’s stream going through my system, in which he pondered how to use the other numbers on the die face of the result you’re using, I realized any roll of 2d4 or more generates additional information that Caltop Core ”Classic” (as I call it) discarded. I started using this information. 

I combined this idea with work I’d done on my own to stretch the system to fit games in the past and came up with this new version. Caltrop Core EX is not quite a “2e.” It’s more of a director’s cut. 

Here’s a summary:

Each player takes turns rolling 3d4. Decide what the total number does, if anything. Decide how the players should use the individual d4 results.

My intent in releasing this is to offer you one more tool to consider when approaching your game idea. I would never ask someone to use my systems for their games if it’s not a good fit. The full doc explores two “modes” for CC EX in the form of examples from my own games. Take what you like, and explore other SRDs here to find the right system for your idea.

Attribution Text

This work is based on Caltrop Core EX, published by Titanomachy RPG. The Caltrop Core EX SRD is licensed for use under a Creative Commons Attribution 4.0 International License. 

CategoryPhysical game
Rated 5.0 out of 5 stars
(14 total ratings)
GenreRole Playing
Tagsd4, dice-core, Indie, poc-made, srd, Tabletop role-playing game


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Click download now to get access to the following files:

Caltrop Core EX.pdf 1 MB


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Could you provide game creation templates, similar to how PUSH provides canva temnplates for the 2-page and the a5 booklet formats? That would help immensely, especially for a lot of us who are overthinkers and/or suck at graphic design.

It reminds me of Otherkind and Ghost/Echo.

(2 edits) (+1)

An interesting evolution to the original Caltrop Core system. EX gives tools and insights gained by the designer's own work with the original system. This makes it more honed. It fleshes out the d4 system by making every result meaningful without sidelining the highest result in your pool.

I'm looking forward to creating with this. And looking forward to what people will make with it too.

It's the macross missile massacre of SRDs.


Cleanly written, nicely presented and with a huge amount of potential. I can't wait to get to work.

Thank you so much!!!!