I loved SotS's focus on simple mechanics that allow player choices to shape the story. A lot of the advice on getting players to provide setting details are practices that I have already used for years, such as having players create atmosphere by having them recount travails of long journeys. It is just nice to see these techniques as an official part of a game. These narrative practices are backed up by mechanics, such as attributes that represent both a value, as well as a pool that can be spent to affect rolls or buy story effects.
In SotS, you use a handful of Investigative and General abilities to shape the world, and thus the story. This allows the game to retain a lot of the simple magic of fantasy roleplaying, which I found dwindling away when I played 3E and 4E briefly. The feel of freedom created by exchanging long lists of KEWL POWURZ for simple narrative mechanics replicates well what Dr Bargle called the Pathetic Aesthetic of the (original, pre 5E) OSR.
I think SotS will be a great antidote to the rules bloat seen in the progression of D&D over editions. With the inclusion of Proficiencies, then Feats & Abilities, D&D killed lots of the magic of play for me by trying to mechanically codify all actions with new rule subsystems. 4e went too far with rules for my taste, while 5e seems a step back to the rulings over rules mode of the original, pre 5E OSR movement.
That said, old D&D and other FRPGS were far from perfect. The OSR added lots of much needed shot of improvisational freedom to gaming, a thing which was lacking when I started playing back in the 80s, when a cult of TSR 'sanctioned' rules defined how many played and ran the game. So instead of going into SotS here, I'd like to think about ways retroclones can be storified in SotS style to promote improvisational DMing and emergent play.
BETTER PRIME REQUISITES
First, the Prime Requisite (PR) of each class serves as 1) an indication of free actions, for which no roll is needed 2) a value for difficult skill tests, and 3) a pool of points to be spent for story effects.For fighters, Strength is the PR, thus any minor action involving Strength does not require a roll but succeeds naturally. For instance, climbing a rope, lifting a barrel, or doing anything a strong person could requires no roll to succeed for a Fighter, whereas other classes would have to make a simple roll. Also, any Strength based action requiring a difficult test for other classes would only require a simple one for Fighters. For example, breaking down an iron door, holding onto a dragon's back, etc. Note that I use d20 resolution for simple tests and d100 for difficult ones, but other DMs are free to use their own system.
Finally, a Fighter player can spend a point of Strength to earn a story effect. Note that this spending doesn't reduce the Strength value for tests, but instead is a limited pool of points that only regenerates after the adventure ends, even if it runs over several sessions, forcing players to spend points wisely. Players are encouraged to creatively narrate the effect, and DMs should refuse boring or unimaginative uses. For instance, a buy of 1 point could allow an unarmed fighter to bend farming tool into a sword for one encounter, or intimidate 1 NPC / monster, or hold onto a ceiling and stay out of sight as a too powerful foe passes.
Other classes can do the same with their PRs. Dexterity for Thieves, Intelligence for Magic Users, and Wisdom for Clerics would offer similar benefits and opportunities to shape the story for players of these classes. Doing so uses the pre-existing attribute system without bloating the rules with ultimately limiting Feats or other subsystems, and instead offering players the chance to use their imagination to shape the story in ways that will surprise and entertain all at the gaming table.
PS: If anyone wants to hear how running SotS went, drop me a line!