As Session 13 looms this weekend, I've begun contemplating several small changes to the Swords & Wizardry rules. All of these changes are the result of my having observed, over the course of three months, how the rules as written have played out in my own campaign. In every case, the changes I'm considering are small and have more to do with the "texture" of play rather than any serious belief that rules X or Y are "broken." That is, I want to build upon the feel that has already grown up in the campaign by slight changes to rules that, in my estimation, run counter to that feel.
Ability Score Modifiers: Having a maximum +1 bonus for scores 13 or better isn't working for me. While it's nice that the rules work against the perceived necessity for very high ability scores, it'd still be nice for a little more mechanical differentiation between, say, having a 13 Strength and a 17 Strength. What I might do is introduce an expanded table that applies only to a character's Prime Attribute, so that Fighters get more Strength options and Clerics more Wisdom options and so on.
Experience Bonus: Again, I appreciate the way that the rules of Swords & Wizardry try to eliminate dump stats by making Wisdom and Charisma important to determining a character's XP bonus, but I've found it somewhat nonsensical in play. In addition, a character with a Prime Attribute, Wisdom, and Charisma 13+ gets a 15% XP bonus, higher than what's possible in OD&D. I'm considering going back to OD&D's Prime Attribute 13-14 = 5% bonus and 15+ = 10% bonus and leave it at that.
Variable Weapon Damage: I have to admit I miss using more than just D20 and D6 in play. In addition, I'm finding that the lack of differentiation between one-handed weapons irksome. I can certainly see why OD&D moved away from universal D6 damage over time.
There are other, bigger changes I might consider introducing at some point, but, because they'd represent fairly significant shifts in the reality of the campaign setting, I'm holding off on introducing them until I can do so with a minimum of disruption.