Currently, cataclysm dda’s preferred method of learning skills seems to be shacking up underground with a horde of food and energy drinks and an atomic lamp, and going to down on a pile of skillbooks for months on end.
I’d like to suggest a way to alter that without having to completely re-write the recipe and crafting system.
First: Remove the ability for the player to gain skill levels from reading books. You can still learn recipes and craft from them, but no longer skill up.
Second: Instead of skilling up by reading the book, having the book nearby when you craft a related recipe will instead enhance the rate at which you learn from crafting. I’m not too good at balance, so I’m just going to pull numbers out of my butt, but feel free to choose your own.
Example: You’re trying to train from rating 8 mechanics to rating 9, and you have a rating 8+ mechanics skillbook nearby, the rate at which you train mechanics while crafting in the vincinity of said book (or if its in your inventory) increases by 40% (or whatever).
Example 2: You’re trying to train from rating 4 cooking to rating 5, and you only have a rating 3 book nearby, you’d still get a exp bonus but to a lesser extent. Say 30% or whatever, and it decreases the further away you skill above the rating of the best book of the related skill you have on hand.
Example 3: You’re trying to train from survival 1 to 2, and have no survival related books on hand. You gain skill experience as normal.
Third: Make it so that having a relevant book on hand of the appropriate skill level gains you a bonus yield on dis-assembly. Having a rating 3 construction book and dismantling a construction-furniture that normally has lossy yields would give less lossy yields on account of you basically having a reference to plan your dis-assembly from.
^ With the above three changes, skill books would still involve a lot of time spent, but it would encourage supply and resource gathering so you can actually craft your skill up, instead of just cuddling up with a book, but would also lessen the resource gathering part slightly to compensate because you could dismantle stuff easier to rebuild.
Another possible change: Give skill/crafting books a durability, and have the books in worse condition give less than optimal exp gain and maybe even have missing recipes and be less valuable. Also, make their condition degrade if you don’t store/treat them properly (but give the ability to keep their condition stable with some minor care and attention, and maybe some chemistry-related ability to attempt to restore their condition to a higher value but risk their destruction in the process) That way finding multiple of the same copy goes from ‘Well, I only need one’ to ‘Found a better one!’