Hello there. What I'm looking to do is change about the relationship between techs and resources. I think it'd be cool if a tech could only be researched if the player had X number of cities with access to Y resource. For example, you can't research Horse Riding if you don't have any horses. I don't think that this is possible as is, but can anyone please give me any help coding-wise or otherwise?

python!!!!!!!!

I was afraid of that. I hate python ;)

It would be possible in the SDK, but their will be a little trickiness in the loading because Techs load before Bonuses so a second processing loop will be required to determine the Bonus TAG name.