I’ve thought about inventions a number of times and how any character can make one. I’ve often thought that a more intelligent character should be able to make a better invention. At times I put this idea off, thinking that a even a less intelligent character may have had some unexpected burst of insight, paid their life savings, or maybe even stole a design. That way any character could have the chance to invent something.
Now I’m thinking about it again. It should be relatively simple to add a character’s Intelligence score to the SP they spend on an invention as a modifier. That would make it necessary to change how many SP the invention items cost or they’ll be thrown out of balance. That’s not a huge deal, It could be done relatively easily.
It would make the Fast Inventions story seed interesting though. A PC with an Intelligence of 9 could cobble together a competent invention by spending 1 SP. In one way, that’s really cool. In another way it could be abused pretty easily.
I’ll mull this over a bit more and it’ would be good to try playtesting it that way to see which ways it would break.
If you want to use the idea, have the inventor character add their SP spent on the invention to their Intelligence attribute and multiply it by 0.75. This is the SP that the character can now spend on the invention.
The SPF avoids math like multiplication to keep things simpler. In a final version the SP and the Intelligence score would just add together and all the invention item costs would be 50% more.