As I have been adding more races, most of them get abilities that they can spend experience on to emphasize their racial power. Gnomes can spend attributes worth of exp to make their tinkering even more powerful. Dwarves can magically gain the ability to see better in the dark. But what about the poor human? What is their special power? What is super unusual about human beings?
(Well other than being super over sexed. We do it far more often than the standard mammal.) Humans are the standard that the other races are measured against. It does not seem that they have any weird things to emphasize. (This hypothetical ability makes the average, EVEN MORE AVERAGE!!!)
Part of the reason I've been giving races the ability to spend a bunch of experience on power ups, is that TFT works better when all attributes are not at 16+. So as the years have gone by, I've found lots of ways for people to spend experience on other things. (e.g. the Piety attribute and superscripts to name just two.)
So I would like to have something that humans can sacrifice experience for to get bonuses.
That thing is Knacks. With most races, you know what you are getting. Gnomes can do Raven things. Elves can get the Gift, "Tree Walking". But humans, have many knacks and they vary a lot. Each player will be given a couple or three random knacks, and may choose to put experience into them. The knacks are often not quite as powerful per experience point as the other races abilities. But an advantage is that no one has any idea of what the Knack is. It makes humans less predictable.
My Knacks need some polishing, but if you should decide to take a human, I will have some knacks for you by the time the campaign starts.