[quote=@TheMushroomLord]
You have my interest. I’d also agree with the above, for these kinds of things keeping it as simple tends to work. I’d even go so far as to say just making a very basic skeleton of a system with only the things you know will be used a lot included and then just improvising the specifics as you go for whatever else comes up is a perfectly valid way to do things. If you want something more concrete than that though I've got some ideas.


[hider=System Idea Thingy]
Everything is broken into Stats, Checks, and Abilities. I'm too tired to write this idea out properly so think D&D to get an idea of how stats and checks would work. 
[b]Stats:[/b] I’d merge Intelligence and Wisdom into one Mind stat, add a Spirit stat for magic, and remove charisma entirely because that can just be roleplayed out. 
[list][*][b]Strength:[/b] Physical output.
[*][b]Toughness:[/b] Ability to take a hit and stamina.
[*][b]Dexterity:[/b] Fine motor skills and agility, maybe those should be split into two different stats.
[*][b]Mind:[/b] Essentially the character's intelligence and wisdom, as well as anything else solely within there, mind that isn't their memories or personality.
[*][b]Spirit:[/b] Magical strength and capacity.[/list]
[b]Abilities:[/b] Players would specify a number abilities which are passive or active abilities they have that distinguish them from average people. This includes the good and the bad as well as both mundane abilities and those resulting from. These could be things as non-specific as the circumstances of the character's background, but the less specific the less the bonus.
[hider=Example Abilities][list][*][b]Light Bearer:[/b] Thanks to a gift they can produce small balls of light from their hands and move them about at will.
[*][b]Stealthy:[/b] They are good at hiding and moving about unnoticed.
[*][b]Bad Hearing:[/b] An accident years ago left them deaf in one ear.
[*][b]Former Sailor:[/b] Has spent years out at sea where they picked up a number of useful tricks for adventuring. [/list][/hider]
[b]Checks:[/b] Checks are a number that is rolled against with a relevant stat modifier applied. DC for any given check is determined by how hard it would be for a normal person (maybe something like, Trivial: 5>, Easy: 6-10, Normal: 11-15, Hard: 16-20, Very Hard: 21-30, Impossible: 30+), and modified by whatever circumstances are relevant to the check as well as the player in questions abilities. 
[hider=Example Scenario][b]Climbing a Cliff Face: [/b] DC 22 Strength Check; Adjusted DC: 17
[list][*][b]Modifier – Plenty of Hands Holds:[/b] -5
[*][b]Modifier – In a Storm:[/b] +5 DC
[*][b]Player Ability – Former Sailor:[/b] Has climbed in far worse storms at sea. Negates penalty from storm.[/list][/hider]
Checks should only be made if it’s reasonable for it to have a chance at working (e.g. a peasant trying to stab a trained fighter is fine despite the low odds, but that same peasant trying to perform brain surgery without training is automatically going to fail). Likewise, the opposite is true when a check could not reasonably be failed. Additionally, things where there shouldn't be any variability in result based on specified actions should not be rolled for. 
[hider=Examples]
[list][*][b]Auto Fail – Untrained Brain Surgery:[/b] Under no feasible circumstances could this ever be at all successful even if theoretically possible, certainly not as a 5% chance. 
[*][b]Auto Success – Assassination:[/b] Slitting the throat of someone that is unaware and unable to defend themselves. No reasonable chance at failure assuming no other factors. Checks may still need to be made for secondary functions, such as doing it quietly.
[*][b]No Check – Discussion:[/b] Many discussions shouldn't require checks. Results should instead be based on the personalities of the participants and their reactions to what specifically has been said.[/list][/hider][/hider]
[/quote]

I quite like this, myself. In the RPs that I used to play in, we eschewed difficulty checks completely and let players just RP things as they decided, using their stats and skills as a reference. In this case though, I wouldn't be opposed to rolls when done like this.