So I've been thinking, why is an unarmored fighter just as easy to hit as an unarmored wizard. Why doesn't the game factor in your ability to parry blows at least in melee

Yeah, I know right. That's one of my beefs with D&D and OSR, a single number called AC does a lot of work. It apparently covers dodging, parrying, and blows that land but are blocked by armor. I don't know why this is, but I'm sure there's a historic reason. Descending AC originally came from ship combat games, did it not?

AC is by far my one and main bugbear (any goblinoid, really) of all the OSR/D&D mechanics that exist. It irks me to no end, even though I have learned to live with it.

I would prefer static AC based on training and experience with armour as damage reduction, but I have learned to live with AC.

Thanks for picking at the scab for me though! 

Quote from: Ocule on December 12, 2021, 04:24:23 PM
So I've been thinking, why is an unarmored fighter just as easy to hit as an unarmored wizard. Why doesn't the game factor in your ability to parry blows at least in melee

In the original combat system used by Dave Arneson, based on Chainmail, a higher level character was harder to hit. So it is definitely an "old school" way to do things. Personally, I use d20+Number of Hit Dice vs 11+ Target's Hit Dice for all combat tests. (with number of hit dice varying by class as in OD&D). For armor, I use an all or nothing Armor saving throw which, again, is based on a system Dave Arneson used in the 70s. For example, wearing leather armor will give you a 17+ save vs all attacks whereas platemaili will give you an 11+ save.

I use an armor saving throw rather than armor reduction because it affects all weapon equally, and it doesn't make a character immune to things like daggers.

Quote from: hedgehobbit on December 12, 2021, 05:15:50 PM

Quote from: Ocule on December 12, 2021, 04:24:23 PM
So I've been thinking, why is an unarmored fighter just as easy to hit as an unarmored wizard. Why doesn't the game factor in your ability to parry blows at least in melee

In the original combat system used by Dave Arneson, based on Chainmail, a higher level character was harder to hit. So it is definitely an "old school" way to do things. Personally, I use d20+Number of Hit Dice vs 11+ Target's Hit Dice for all combat tests. (with number of hit dice varying by class as in OD&D). For armor, I use an all or nothing Armor saving throw which, again, is based on a system Dave Arneson used in the 70s. For example, wearing leather armor will give you a 17+ save vs all attacks whereas platemaili will give you an 11+ save.

I use an armor saving throw rather than armor reduction because it affects all weapon equally, and it doesn't make a character immune to things like daggers.

Sounds pretty adaptable to various system and actually takes them into account. So it scales pretty much 1:1 with bonus to hit/thac0/whatever youre using?

Do any OSR games run with this premise already in mind?

Well, if you add hit points (particularly the non-meat portions) into the equation then Armor Class resolves rather nicely. AC is basically your passive defense, a guy swings at you and better armor means some stuff just bounces off. Then hit points are you expend as active defense to parry or dodge attacks that your armor fails to stop.

In the case of the unarmored wizard and fighter both would need active defense to avoid a sword strike... but the wizard has a d4 HD and the fighter has a d10 HD so, even with completely average Constitutions, by level 4 the wizard can actively defend against only about 10 hp while the fighter can actively defend against 22 hp before being overwhelmed.

It's the two (AC + hit points) working together that create a reasonably realistic depiction of active and passive defenses... at least for that particular balance of realism vs. speed of play.

Quote from: Chris24601 on December 12, 2021, 07:04:31 PM
Well, if you add hit points (particularly the non-meat portions) into the equation then Armor Class resolves rather nicely. AC is basically your passive defense, a guy swings at you and better armor means some stuff just bounces off. Then hit points are you expend as active defense to parry or dodge attacks that your armor fails to stop.

In the case of the unarmored wizard and fighter both would need active defense to avoid a sword strike... but the wizard has a d4 HD and the fighter has a d10 HD so, even with completely average Constitutions, by level 4 the wizard can actively defend against only about 10 hp while the fighter can actively defend against 22 hp before being overwhelmed.

It's the two (AC + hit points) working together that create a reasonably realistic depiction of active and passive defenses... at least for that particular balance of realism vs. speed of play.

I'm ok with this in principle, but how many HP represent the meat and how many represent the active defense?

Quote from: Heavy Josh on December 12, 2021, 07:45:15 PM

Quote from: Chris24601 on December 12, 2021, 07:04:31 PM
Well, if you add hit points (particularly the non-meat portions) into the equation then Armor Class resolves rather nicely. AC is basically your passive defense, a guy swings at you and better armor means some stuff just bounces off. Then hit points are you expend as active defense to parry or dodge attacks that your armor fails to stop.

In the case of the unarmored wizard and fighter both would need active defense to avoid a sword strike... but the wizard has a d4 HD and the fighter has a d10 HD so, even with completely average Constitutions, by level 4 the wizard can actively defend against only about 10 hp while the fighter can actively defend against 22 hp before being overwhelmed.

It's the two (AC + hit points) working together that create a reasonably realistic depiction of active and passive defenses... at least for that particular balance of realism vs. speed of play.

I'm ok with this in principle, but how many HP represent the meat and how many represent the active defense?

Does it really matter? Adding unneeded complexity to a system that works is pointless.

Quote from: Ocule on December 12, 2021, 04:24:23 PM
So I've been thinking, why is an unarmored fighter just as easy to hit as an unarmored wizard. Why doesn't the game factor in your ability to parry blows at least in melee

"Touch" AC has been around for a while. Your AC with only Dex bonus. I want to say I've seen it as early as AD&D, for certain effects, but I can't remember precisely.

Parry rules were introduced in 2nd edtion as an alternate rule in the Fighter's Handbook I think.

Quote from: Heavy Josh on December 12, 2021, 07:45:15 PM

Quote from: Chris24601 on December 12, 2021, 07:04:31 PM
Well, if you add hit points (particularly the non-meat portions) into the equation then Armor Class resolves rather nicely. AC is basically your passive defense, a guy swings at you and better armor means some stuff just bounces off. Then hit points are you expend as active defense to parry or dodge attacks that your armor fails to stop.

In the case of the unarmored wizard and fighter both would need active defense to avoid a sword strike... but the wizard has a d4 HD and the fighter has a d10 HD so, even with completely average Constitutions, by level 4 the wizard can actively defend against only about 10 hp while the fighter can actively defend against 22 hp before being overwhelmed.

It's the two (AC + hit points) working together that create a reasonably realistic depiction of active and passive defenses... at least for that particular balance of realism vs. speed of play.

I'm ok with this in principle, but how many HP represent the meat and how many represent the active defense?

Depends on the system. My own game uses "hit points" that are entirely non-physical (actual wounds are reflected via "afflictions" like Head Injury, Injured Arm, Injured Leg and Internal Injuries that takes days or weeks to heal without magic and can worsen and even kill the character).

On the other hand when it came to a lot of the old school games I have heard about the general assumption was that only your first hit die was physical, the rest was mostly skill, stamina, spirit, luck, etc. It didn't matter much in play because non-magic healing was the same rate regardless... but it did provide a convenient breakpoint in that PCs had basically the same level of meat as generic human monsters (1 HD bandits and soldiers and the like) and at higher levels it was the other factors that kept you in the fight longer.

The more Modern variant of this is basically the Wound Point/Vitality Point system that first turned up in d20 Star Wars and then was added to the Unearthed Arcana material. It used your Con score for wound points and Con-modified Hit Dice for your vitality points. Vitality recovered quickly, wounds not so quickly... and critical hits would bypass vitality and do damage direct to wounds.

Quote from: Ocule on December 12, 2021, 04:24:23 PM
So I've been thinking, why is an unarmored fighter just as easy to hit as an unarmored wizard. Why doesn't the game factor in your ability to parry blows at least in melee

You might as well ask why a fighter has more hit points than a magic-user. Hit points are greater for fighters than magic-users, and increase each level. You might also ask why a magic-user's hit points ever increase.

Hit points obviously do not represent entirely structural changes, or the naked 6th level fighter would be built like a rhino. Nor is there any logical reason to expect that a 2nd level magic-user, having as they will 2-8 hit points with an average of 5.0, should be as physically sturdy as a 1st level fighter with 1-10 hit points and an average of 5.5.

As well as structural changes in the person's physique, hit points represent as well dodge, parry and fatigue, and fatigue from dodging and parrying. And this is why a fighter generally has more hit points than the same level magic-user, and it's why their hit points both rise each level. And it's why a 2nd level magic-user has the same average hit points as a 1st level fighter - the magic-user has become more practiced in getting out of the way.

This is the problem with merely reading a game system rather than playing it. All game systems are abstractions - all of them. And all game systems at their finest level of abstraction are nonsense - all of them. But if you have a well-designed game system, then those fine elements together will produce something which makes sense.

By itself, armour class makes no sense. By itself, levelling up makes no sense. By itself, hit points make no sense. But when you put these things together, you get something which is of course not realistic, but is reasonable.

Quote from: Ocule on December 12, 2021, 04:24:23 PM
So I've been thinking, why is an unarmored fighter just as easy to hit as an unarmored wizard. Why doesn't the game factor in your ability to parry blows at least in melee

Why does the dog move faster than the racecar?  How can the top hat, shoe, or iron move under their own power at all?

D&D is abstract for simplicity.
If you want crunchy combat pick up Gurps or RoleMaster.

An old school element in D&D having elements that are not a perfect fit?

SHUT UP! How DARE you! Old school elements where perfect until whiners DARED attempt to improve on them in any way.
Thats the real reason man was cast down from heaven. Because Eve asked if they could use a armor as damage reduction system!

Quote from: Kyle Aaron on December 12, 2021, 10:07:53 PM
By itself, armour class makes no sense. By itself, levelling up makes no sense. By itself, hit points make no sense. But when you put these things together, you get something which is of course not realistic, but is reasonable.

The single most dominant trait in the role playing community is spending time and emotional energy upon whatever does not appeal to you.  Even though these are finite and incredibly valuable.