No Rules No Rulings
When running Wolves Upon the Coast, a situation arose - the players wanted to train the griffon chicks they had adopted (stolen). There is nothing in rules for this. In most retro-clones and ‘comprehensive’ adventure game systems, you could use some of the existing attributes as a “fallback” - usually falling on Intelligence or Wisdom in my experience, although Charisma would be a possible candidate here.
Wolves has no such attribute* - and as such, I was forced to come up with something. I think this is notable outside of the normal mantra of “rulings not rules” as this isn’t a reusable solution which becomes part of the ‘house rules’ - this is a bespoke, one-off thing for this exact situation. The exact specifics don’t matter so much as the process of evaluation and development on-the-fly, using the techniques of player consensus to get agreement before actually putting it into practice. Additionally, we can consider non-attribute elements such as prior training (as indicated by starting equipment) and general conduct. This isn’t unique to operating in this way, but is always worth pointing out.
(As it happens, I did a simple d20 roll - 1 or 2 representing disaster, 19 or 20 representing incredible progress. The players were able to dial these in - giving more freedom increasing the risk of disaster and the chances of success. Additionally, they were able to suggest ways to mitigate some of the risk. This gave them real ownership of the roll and it’s results. This only made it funnier when one of the griffons became a good boy and the other one ate two dogs.)
*It only has Strength, Constitution and Dexterity.