Here is an idea for you... you can create hidden resources that serve absolutely no purpose. Make one where everyone has 100 of such a resource. You can increase this resource (I suspect) with the tag above. Set a game event (you get a hero type thing that checks for resource meeting a threshold, once reaching that threshold you can give each player the set amount of resource that you wanted to in a game event (similar to fame increase).
create undetectable resource that everyone starts with a fixed amount...
Increase undetectable resource with tag above (untested, hope it would work)
Define a quest game event similar to CoreGameEvents waiting for a resource threshold to be met.
That game even should give as a reward the fixed integer amount of resource. (be sure to not let them deny the choice)
--- untested, but I think it should work ---