D&D has had a sophisticated, elegant, quick task resolution system open to player skill, DM interpretation, and significance of characteristics for decades: The Reaction Table.
A simple roll of dice, a wide range of results. I'm going to go with a few examples here as I feel they illustrate the point rather well.
A Simple Unified Task Resolution Table (based on the Reaction Table)
2- Dismal Failure
12+ Extremely Favorable
Suggestions not hard rules, they could be written into a scenario but are more appropriate of the type of chart inspired ruling a DM could make in various situations based on a reaction table based methodology.
#1 So you want to climb that rough rocky 100’ tall cliff…. You have ropes +1, oh no the rocks are slippery with ice -2, you have good dexterity and strength and you aren’t encumbered +1.
Dismal Failure- drop to your doom.
Unfavorable- this is hard and dangerous you get 20’ up, further attempts will be at -1.
Uncertain… make a saving throw! Fail it and no progress, succeed and you make it halfway up.
Favorable- going well, you make it 50’ up, next roll is +1
Extremely Favorable- you make it up the cliff face, any of your companions following you get +2 to their rolls.
#2 You have offended Witch-Queen and she’s pointing her wand and you want to talk your way out of it:
High charisma: +2, Player says something stupid or mumbles and stumbles -3 .
Dismal Failure- she’s unimpressed with your feeble whimpering and zaps you with her wand… save at -2
Unfavorable- maybe you should have ran for it instead, make a save vs wands,
Uncertain… keep talking, she hasn’t zapped you yet
Favorable- the Witch-Queen lifts an eyebrow and the tip of her wand lowers…
Extremely Favorable- She laughs and sets her wand aside, maybe you can be of some use to her…
#3 Picking a lock on a 50 year old door with a lock built by the Grumble Brothers.
You have lock picks, you are a trained thief +2, The lock is a bit dirty and stiff -1, The grumble brothers made very good locks -2. Only an improvised pick -5.
Dismal Failure- your lock pick snaps and is wedged in the lock, looks like you are going to need an axe to get through this door.
Failure- nope, just can’t do it, you lack the skills and tools.
Uncertain- not done yet, just a little more and you might get it (roll again)
Favorable- oh a click, you’ve picked the lock
Extremely Favorable- oh that was easy, and you’ve learned more about Grumble Brothers locks: +1 to pick one next time you find one.