HGG Community Forums

In order to paper horses you need at least a basic upgrade. Papers tell you how good of a breeder the horse should be. Mares and stallions have different paper names.

From the FAQ page:

Stallion Papers
Showable Only: This means just that, should only ever be used for showing. Consider it a definite fail as far as breeding stock is concerned.
C: This represents basic/foundation level breeding ability. Perfect quality foundation stallions are C-papered.
B: Exceptional foundations and many 2nd generation stallions are B-papered.
A: Only exceptional foundations that have been given 5% breeding boosts can expect to see A papers. Otherwise, these are sometimes bred in the 2nd generation, and often in the 3rd.
*Star: This is the highest a stallion can paper. You normally will find this, albeit rarely, in boosted 3rd generation lines - most often in 4th and beyond.
Mare Papers
Failed: The mare equivalent of a stallion's "Showable Only" result. This mare has no place breeding
Yellow: This represents basic/foundation level breeding ability
Red: Exceptional foundations and many 2nd generation mares are Red-papered
Blue: Only exceptional foundations that have been given 5% breeding boosts can expect to see Blue papers. Otherwise, these are sometimes bred in the 2nd generation, and often in the 3rd.
*Gold: This is the highest a mare can paper. You normally will find this, albeit rarely, in boosted 3rd generation lines - most often in 4th and beyond.

So a C papered stallion is comparable to a Yellow papered mare, B to Red, A to Blue, And *Star to *Gold. I recommend breeding like this as it will increase the number of intact foals you get because the parents are of similar breeding ability.