HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

In Heroes 5, there's a building that allows you to forget some skills and learn new ones upon leveling up (if I'm not mistaken). I'm not sure how well this would translate to Heroes 3, but I'd like to see something similar here. Forgetting skills would cost gold/resources, and it should be expensive enough to avoid being overpowered, perhaps with a level requirement, etc.