FATE Accelerated or FAE (for short) is a great system if you want to focus more around the narrative or
FATE core if you want a bit more depth added in. It's just a great system fixated more on storytelling then anything that can work in any sort of setting. You use special Fate dice (just D6 dice with a success, fail, or nothing, which you can just attribute 1-2 = -1 3-4 = 0 5-6 = +1) where after rolling you determine how successful you are (or not) if you meet the check.
You have Aspects which are basically describing your character and what they are like. So say you are a "Cowboy who works against the law to achieve what they believe to be true justice" would be what you would aim your character to be like. If something happens in the story where you know a criminal is in town but is protected by the law, you could be compelled by the GM to act in that way despite the trouble it might cause. Doing so can then earn you a Fate point (Special points you can use to add certain aspects to increase your bonus towards overcoming a task among other things) from doing something that negatively effects your character.
Approaches (effectively skills in like DND or Pathfinder) which are
- Careful
- Clever
- Flashy
- Forceful
- Quick
- Sneaky
which you would put points into creating your character. When you have an obstacle to overcome, you would pick an approach to use based off how you go to solve the problem (given GM approval) at that point you use the value your character has in the skill to determine the result
Lastly there are stunts which might be included to add extra effects. Not nessisarily needed most games I played they weren't included but effectively consider it extra bonuses that can be applied.
It's very open ended as a system and very much can be tweaked or expanded on as you like with the FATE core adding more to the system though it's still by far very rules light. The big benefit is it can work in any setting. I've used FAE in an Avatar the Last Airbender RP, a lovecraftian horror story, a somewhat ironically Fate series RP, and a retrotech space adventure. Very narrative focused for a system.
PDF can be obtained here. They have a pay what you want system though you don't need to pay either, more a 'if you want to support them' deal. The FATE core though is paid for as far as I know. Decently long length wise though it explains things out mostly for the GM. Near the back is a quick reference chart that is honestly enough in those two pages to get a general idea how to play. My description is probably far from the best/cleanest and I've only really been a player though I've found it simple enough to jump in, and it has plenty of room to add in more elements if you want to say add advancement/leveling of some sort or anything else to 'progress' the characters through the story.