Can we please for the love of all thats good in gaming not do random roll-like style... Imagine this... you're playing minecraft for 6 hours straight not doing anything stupid so you don't ever die... The gods have smiled upon you and now you're level 50. so you wip out the enchanting table and WAM life slaps you across the face... you got efficiency when you wanted silk touch.
Yeah, these things are a cascade problem for me. I will avoid dice rolls wherever possible. Otherwise, a dice roll implies some "skill" and a "skill" implies progression (experience) and "progression" implies killing 900 badgers to gain a level. No, thanks. Because the other side of the "kill 900 badgers" issue is that badger "drops" have to be so worthless that you don't get rich by killing 900 of them... because I'd obviously have to spawn them pretty frequently.
Where a dice roll will potentially come into play (and I'm not saying it will just that it might) is when a character has recently readjusted their attributes... so maybe they found a way to bump their strength up. Now any task they perform that requires carefully balancing their strength with their aim (say, pounding some delicate thing with a hammer) may have an extra chance of screwing up a little. So, if you have just increased your strength then you might want to practice a few times on stuff you don't care about. Then you're fine and can master craft what you want with confidence. Any random mistakes after that will be minor and correctable... converging eventually on a 0 chance of mistakes (the master craftsman).
Otherwise, the kinds of things you can screw up are player skill issues. If you are holding your sword into the forge to start the tempering process it requires it to reach a certain temperature but not go above some other temperature. This might be indicated by the color of your reticle (the little crosshair cursor thingy). So you get a feel for what shade of orange it should be before you pull it out or whatever. Pull it out too soon or too late and you've messed up the temper of the metal and may have to go back to a previous point in the process or melt it all down and start over. If you even care about properly tempering the blade (speaks to quality and durability). And the margin of error will be wide enough that it's not overly tricky but does require paying attention. For example, if you were a really good black smith then you might be able to put a few swords in the fire at once and just keep track of their temperature from time to time to pull them out when appropriate.
A little more on my aversion to dice rolls and the 900 badger problem without going too far off topic... these things tend to shrink a world also. Too often you end up with the situation where the "town is a safe place" and just outside of town is the "newb monsters" so that you can earn your XP and venture farther out. Eventually when you are level X you are good enough to venture to the next town without getting mauled by a boar. It's kind of a trick for places that have relatively small finite worlds because they don't want you to reach the edge too quickly.
I would prefer to let players wander a little more safely. If you stay to the roads then travel should be relatively safe from creatures because most animals will avoid man unless their forests are over-hunted. In this kind of system, I'm not always randomly spawning in creatures. They become (at least collectively) more persistent almost like NPCs. The smaller vermin (rabbits, squirrels, etc.) are a random function of the quality of the wilderness there. But a wolf pack is a thing on its own with a life cycle, resource needs, etc... hunting is plentiful and the pack will thrive and never hit the roads. Hunting is not plentiful (say because the woods is overhunted or because someone burned down most of it) and the wolves start to venture out onto the roads looking for a meal or maybe even heading into to town to steal a chicken or two if they are really hungry. But because the pack is a "thing" you and a band of adventurers could conceivable go kill them all and now their would be no more wolves in that forest. Now you have the opposite problem. The woods is so plentiful with mice, squirrels, rabbits, etc. that they start stripping vegetation, infesting the local villages, eating the crops, etc..
If I had to balance a world like that so that a player could kill 900 badgers then level 50 characters would be neck deep in dead badgers just having walked to the next town. Again, no thanks.
Random even more off-topic aside, I'm heavily influenced by a pencil and paper RPG system called Runquest that was out in the 80s and you could find it out of print in the 90s. It's an experienceless system though it does have buildable skills. The systems in this game always made so much sense it's affected everything I've done ever sense in some way. Anyway, I noticed the other day that a few years ago they finally updates and published a new version of this game. Kind of cool for anyone who wants to get a taste of something different than the complexity of the D&D system ("Wait, what's the effect of my +2 sword on an AC 6 creature when my strength is 18?")
