Since I've got a bug up my butt about running Temple of Elemental Evil (For better for for worse), I'm looking through some of the OSR material I have as well as the TSR options. I've seen a few things I really like or are at least notable. A lot of this comes from the Adventurer Conqueror King System (ACKS) with a eye on Astonishing Swordsmen and Sorcerers of Hyperborea (ASSH). But some of it might be doable in a 5th edition game or 13th Age, not just TSR D&D or an OSR retroclone or whatnot, but some are really tied to those older d20 rolling fantasy games.
1) Warrior damage bonus and cleaving. ACKS just flat-out gives warriors a scaling damage bonus from +1 at first level to +5 at 12th Level. It reminds me of weapon specialization in AD&D. At some point, fighters just need to be doing a little more damage. I'm just not quite sure what the correct amount is, but something simple like +1 at levels 5, 10, 15, and 20 surely can't be overpowered. Weapon Mastery (double specialization) and beyond show up in Combat & Tactics as single-classed fighter only options which is nice, but guarantees that fighters become very kensei-like and overspecialized in a single weapon. I like the option, but I'm unsure what the implementation ought to be. ASSH gives fighters a couple weapons that they get +1 hit/damage with over their careers and the option to double specialize in one. I like the kensei class option in greater specialization, but maybe its not for all warriors.
2) Warrior cleaving. First edition had a somewhat hidden/obscure rule (well, lots really) that allowed a fighter to make a number of attacks equal to his level against creatures less than 1/2 hit die. It gets repeated in a number of OSR books, and adapted a little by Combat and Tactics. But I like the ACKS implementation mostly though it might need a slight tweak. When a warrior kills an enemy, they get to make a bonus attack with the same weapon against an enemy within 5' (though if they have movement they can still move 5' and make the attack). They can do this a number of times equal to their level. Clerics and Thieves can do it up to half their level. That's powerful! Removing the hit die cap (which is what ACKS appears to do) makes it much easier to use. Combat & Tactics specifies you must be outnumbered to use the rule, and it might still have a hit die limit. I like the idea of a scaling Hit die limit still. Though a "kill in one blow" wording might de-facto do an appropriate hit die limit. Combat & Tactics limits the number of bonus attacks, giving double your normal attack rate as the limit, which I kinda like. But some version of this really gives a nice bonus to warriors. Note that, depending on the wording, this warrior cleave or heroic fray might work for missile attacks as well, not just melee.
3) Encumbrance in Stone. Its around the internet in a few places, but ACKS uses is too. Basically, you use a much larger weight unit so encumbrance has a better level of granularity. ACKS defines a stone as 10 pounds, but the 14-pound stone is still used in the UK as a unit of human body weight. However you define it, you're dealing with numbers in the range of 20 or less usually, so that's a bit easier to math out.
4) Rations. DungeonWorld and ACKS use a nicer ration system, though its there in all forms of TSR D&D too. It could just be a little simplified. TSR D&D never gave lots of healing overnight though, which is where rations might be more important for a game like 5th edition or 13th Age where you fully heal (or more fully heal) overnight. I actually did something like this in the 4th edition Dark Sun game I ran, which was letting the PCs cast defiling magic to regain all their healing surges while they were travelling. It made wilderness encounters actually worthwhile since you might actually lose resources on the way to the dungeon. Normal AD&D makes regaining HP difficult enough unless the cleric totally blasts the party with cure light wounds.
5) Dual Wielding. In ACKS, dual wielding just gives you an offensive bonus, not extra attacks. Extra attacks should, I feel, be limited to special situations and certain classes (warriors in general, the monk specifically). I also like the 13th Age take on dual wielding, but extra attacks can get pretty powerful (especially when you have magic bonuses to hit and damage in addition to ability score bonuses) and they can be a pain to deal with consistently. Saying that though, some missile weapons in TSR D&D more readily get multiple attacks, particularly with weapon specialization.
4) XP for gold and Carousing (i.e. gold for XP). I can see how gaining XP based on the loot you get makes the game a bit more Sword-and-Sorcery than high fantasy. So I like it. I also agree that its maybe best if you get the XP for magic items you sell (but don't use): so its really for gold you're bringing back to town. ACKS has a carousing rule which says you can piss away that gold and start an XP bank for your next character. I kinda like that idea too. Again, not sure the best implementation, but I like the idea. However, this doesn't look like it'd work well in a game like 5th edition or 13th Age: something about those distinct XP charts for classes and AD&D multiclassing makes this feel like it works best in those games. When you either don't really pay attention to XP (or gold, for that matter) and just give out level-ups for milestones or whatnot, it doesn't seem to matter.
5) Simplified weapons. ACKS does a 5th edition on weapons a bit, taking the broad number of weapons down from AD&D's massive set. I like the idea, but I also like the notion of weapon properties. A few more properties might play up some more differences between weapons, like flails and chains ignoring shields (wrap around) and entangling enemies (easier to disarm or trip). You could even capture some of the weapon vs armor stuff of AD&D with properties like plate-penetration or whatnot. Certainly they must have considered this in 3rd edition and decided against it for some reason, but I'm not privy to what that reason was so it still seems worthwhile to simplify the weapons slightly but keep some of the crazier properties and oddities of the system. Maybe the properties could be steamlined a bit to generic +2/-2 so its easier to keep track of though.
6) Shield sundering (and more). Though I can't seem to find it in ACKS, the internet claimed there was a shields-will-be-sundered rule. I'm not sure I like the option where you can just let your shield break anytime for half-damage, but I like weapons and shields breaking. Its part of the reason why I'm thinking one benefit of fighters is they should automatically get something like tight-group proficiency with weapons and be able to use more weapons, rather than funnel them into grand-mastery specialization with just one weapon. I wonder if this might be great as an alternative to some critical hit nonsense. Crits and fumbles might where your equipment has a chance to break (or enemies equipment does) rather than always just doing something like max damage. Actually, I really like the idea of crits doing things like breaking equipment in addition to or instead of just heaps of damage. Cause unless you have a max damage on crits rule, just rolling double dice can be a bummer when you roll 1s on the damage die for a crit.
7) Wisdom (and Charisma) for bonus XP. This comes out of Swords and Wizardry, where your prime requisite bonus is only 5%. A wisdom or charisma of 13+ gives you a 5% bonus to XP as well. I'm not so sure I like it for Charisma, but any class with a better wisdom seems like it should get that XP bonus. I might give the Cha bonus for classes who would otherwise be required to have a good wisdom like Clerics or a Necromancer rather than letting wisdom do double duty there. But Wisdom as a prime requisite for all classes might be nice.
8) Spell preparation. ASSH uses the TSR / vancian method of fire-and-forget. But ACKS uses the method that classes like the Spirit Shaman of 3rd edition or now 5th edition use. A wizard's spellbook lets him practice/prepare a set of spells, but the spell slots themselves are also magic points used to cast those spells. In this case, the wizard is a little more versatile. Clerics in ACKS, it seems, have their whole list prepared! I do like the 5th edition system a little, but is is odd if you have 2nd level slots left and need to cast a first level spell. I'm not sure about this, but see scrolls below.
9) Scrolls. ASSH gives mages the ability to scribe scrolls right away at first level. This is a case where I'm not sure I like it. Scribe Scroll seemed quite potent in third edition, so allowing wizards to explicitly scribe scrolls at low levels seems a lot. Mostly because at mid and higher levels, the wizard is only spending a pittance of XP or gold to have a good number of useful low-level scrolls scribed. Now, a game where you still use your own slots or magic points to power a scroll might make it more interesting and balanced: you're scribing the scrolls to expand your repertoire but not your number of spells cast per day. Depends on your rules, perhaps. Though that wouldn't fit with thieves being able to read a scroll on occasion, though maybe you could also rule you lose 1d4hp per level of the spell if you don't use a slot to cast that spell.
There's a whole lot of other options out there, but the Player's Option books and the OSR literature don't always make this stuff easy to find. Also, deciding on what to implement isn't easy. I'm guessing a lot of this stuff wasn't playtested as well as it could be, and what works well in one system or even gaming table might not translate at all to another. More reading to do, I suppose, but this was a first pass at some interesting options.
1) Warrior damage bonus and cleaving. ACKS just flat-out gives warriors a scaling damage bonus from +1 at first level to +5 at 12th Level. It reminds me of weapon specialization in AD&D. At some point, fighters just need to be doing a little more damage. I'm just not quite sure what the correct amount is, but something simple like +1 at levels 5, 10, 15, and 20 surely can't be overpowered. Weapon Mastery (double specialization) and beyond show up in Combat & Tactics as single-classed fighter only options which is nice, but guarantees that fighters become very kensei-like and overspecialized in a single weapon. I like the option, but I'm unsure what the implementation ought to be. ASSH gives fighters a couple weapons that they get +1 hit/damage with over their careers and the option to double specialize in one. I like the kensei class option in greater specialization, but maybe its not for all warriors.
2) Warrior cleaving. First edition had a somewhat hidden/obscure rule (well, lots really) that allowed a fighter to make a number of attacks equal to his level against creatures less than 1/2 hit die. It gets repeated in a number of OSR books, and adapted a little by Combat and Tactics. But I like the ACKS implementation mostly though it might need a slight tweak. When a warrior kills an enemy, they get to make a bonus attack with the same weapon against an enemy within 5' (though if they have movement they can still move 5' and make the attack). They can do this a number of times equal to their level. Clerics and Thieves can do it up to half their level. That's powerful! Removing the hit die cap (which is what ACKS appears to do) makes it much easier to use. Combat & Tactics specifies you must be outnumbered to use the rule, and it might still have a hit die limit. I like the idea of a scaling Hit die limit still. Though a "kill in one blow" wording might de-facto do an appropriate hit die limit. Combat & Tactics limits the number of bonus attacks, giving double your normal attack rate as the limit, which I kinda like. But some version of this really gives a nice bonus to warriors. Note that, depending on the wording, this warrior cleave or heroic fray might work for missile attacks as well, not just melee.
3) Encumbrance in Stone. Its around the internet in a few places, but ACKS uses is too. Basically, you use a much larger weight unit so encumbrance has a better level of granularity. ACKS defines a stone as 10 pounds, but the 14-pound stone is still used in the UK as a unit of human body weight. However you define it, you're dealing with numbers in the range of 20 or less usually, so that's a bit easier to math out.
4) Rations. DungeonWorld and ACKS use a nicer ration system, though its there in all forms of TSR D&D too. It could just be a little simplified. TSR D&D never gave lots of healing overnight though, which is where rations might be more important for a game like 5th edition or 13th Age where you fully heal (or more fully heal) overnight. I actually did something like this in the 4th edition Dark Sun game I ran, which was letting the PCs cast defiling magic to regain all their healing surges while they were travelling. It made wilderness encounters actually worthwhile since you might actually lose resources on the way to the dungeon. Normal AD&D makes regaining HP difficult enough unless the cleric totally blasts the party with cure light wounds.
5) Dual Wielding. In ACKS, dual wielding just gives you an offensive bonus, not extra attacks. Extra attacks should, I feel, be limited to special situations and certain classes (warriors in general, the monk specifically). I also like the 13th Age take on dual wielding, but extra attacks can get pretty powerful (especially when you have magic bonuses to hit and damage in addition to ability score bonuses) and they can be a pain to deal with consistently. Saying that though, some missile weapons in TSR D&D more readily get multiple attacks, particularly with weapon specialization.
4) XP for gold and Carousing (i.e. gold for XP). I can see how gaining XP based on the loot you get makes the game a bit more Sword-and-Sorcery than high fantasy. So I like it. I also agree that its maybe best if you get the XP for magic items you sell (but don't use): so its really for gold you're bringing back to town. ACKS has a carousing rule which says you can piss away that gold and start an XP bank for your next character. I kinda like that idea too. Again, not sure the best implementation, but I like the idea. However, this doesn't look like it'd work well in a game like 5th edition or 13th Age: something about those distinct XP charts for classes and AD&D multiclassing makes this feel like it works best in those games. When you either don't really pay attention to XP (or gold, for that matter) and just give out level-ups for milestones or whatnot, it doesn't seem to matter.
5) Simplified weapons. ACKS does a 5th edition on weapons a bit, taking the broad number of weapons down from AD&D's massive set. I like the idea, but I also like the notion of weapon properties. A few more properties might play up some more differences between weapons, like flails and chains ignoring shields (wrap around) and entangling enemies (easier to disarm or trip). You could even capture some of the weapon vs armor stuff of AD&D with properties like plate-penetration or whatnot. Certainly they must have considered this in 3rd edition and decided against it for some reason, but I'm not privy to what that reason was so it still seems worthwhile to simplify the weapons slightly but keep some of the crazier properties and oddities of the system. Maybe the properties could be steamlined a bit to generic +2/-2 so its easier to keep track of though.
6) Shield sundering (and more). Though I can't seem to find it in ACKS, the internet claimed there was a shields-will-be-sundered rule. I'm not sure I like the option where you can just let your shield break anytime for half-damage, but I like weapons and shields breaking. Its part of the reason why I'm thinking one benefit of fighters is they should automatically get something like tight-group proficiency with weapons and be able to use more weapons, rather than funnel them into grand-mastery specialization with just one weapon. I wonder if this might be great as an alternative to some critical hit nonsense. Crits and fumbles might where your equipment has a chance to break (or enemies equipment does) rather than always just doing something like max damage. Actually, I really like the idea of crits doing things like breaking equipment in addition to or instead of just heaps of damage. Cause unless you have a max damage on crits rule, just rolling double dice can be a bummer when you roll 1s on the damage die for a crit.
7) Wisdom (and Charisma) for bonus XP. This comes out of Swords and Wizardry, where your prime requisite bonus is only 5%. A wisdom or charisma of 13+ gives you a 5% bonus to XP as well. I'm not so sure I like it for Charisma, but any class with a better wisdom seems like it should get that XP bonus. I might give the Cha bonus for classes who would otherwise be required to have a good wisdom like Clerics or a Necromancer rather than letting wisdom do double duty there. But Wisdom as a prime requisite for all classes might be nice.
8) Spell preparation. ASSH uses the TSR / vancian method of fire-and-forget. But ACKS uses the method that classes like the Spirit Shaman of 3rd edition or now 5th edition use. A wizard's spellbook lets him practice/prepare a set of spells, but the spell slots themselves are also magic points used to cast those spells. In this case, the wizard is a little more versatile. Clerics in ACKS, it seems, have their whole list prepared! I do like the 5th edition system a little, but is is odd if you have 2nd level slots left and need to cast a first level spell. I'm not sure about this, but see scrolls below.
9) Scrolls. ASSH gives mages the ability to scribe scrolls right away at first level. This is a case where I'm not sure I like it. Scribe Scroll seemed quite potent in third edition, so allowing wizards to explicitly scribe scrolls at low levels seems a lot. Mostly because at mid and higher levels, the wizard is only spending a pittance of XP or gold to have a good number of useful low-level scrolls scribed. Now, a game where you still use your own slots or magic points to power a scroll might make it more interesting and balanced: you're scribing the scrolls to expand your repertoire but not your number of spells cast per day. Depends on your rules, perhaps. Though that wouldn't fit with thieves being able to read a scroll on occasion, though maybe you could also rule you lose 1d4hp per level of the spell if you don't use a slot to cast that spell.
There's a whole lot of other options out there, but the Player's Option books and the OSR literature don't always make this stuff easy to find. Also, deciding on what to implement isn't easy. I'm guessing a lot of this stuff wasn't playtested as well as it could be, and what works well in one system or even gaming table might not translate at all to another. More reading to do, I suppose, but this was a first pass at some interesting options.
