D&D 5E Armour house rules for a low-tech setting. Do these seriously break anything?

[Crimson Longinus]

So I've been working on this setting where the most advanced civilisations are on early bronze age tech-level and a lot of the world is basically at the late stone age. So reflect this I want to make armour less necessary, but still not remove it completely. The basic idea is lessen the AC increase that armour gives, but let characters to add half of their proficiency bonus (rounded down) to their AC.

So light armour is basically gone. Or it at least provides no benefit unless magical. This means that casters and light armour users both use the 'unarmoured' column of the table. This benefits casters a bit, so I might compensate by removing Mage Armour spell. It is a boring tax spell anyway. Now you don't have it but your standard AC is better. I also changed how Unarmoured Armoured Defence Class Feature works to be more consistent with these rules.

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(The table also only contains useful armour, I didn't want armours who were just objectively worse in every way except cheaper. So now there should be some benefits and drawbacks in every armour.)

Light/no Armour
Unarmoured	Free	11+ ½ prof + dex mod
(Unarmoured Armoured Defence)	(Class Feature)	11+ prof + dex mod
Medium Armour
Leather Armour	Cheap	13+ ½ prof + dex mod (max2)
Composite Armour*	Kinda cheap	14+ ½ prof + dex mod (max2)	disadvantage
Heavy Armour
Scale Armour	A bit expensive	16+ ½ prof	disadvantage
War Panoply**	Crazy expensive	17+ ½ prof	disadvantage	Speed -5

* This is basically a leather armour reinforced with some bones, bronze bits etc.
** This is a heavy bronze plate armour like Dendra Panoply (though maybe quite not so goofy looking.)

Shields work as normal.
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So does this terribly break anything? I know ACs scale now a bit while they otherwise wouldn't, but maybe two points across twenty levels is not so big of a deal? Especially as that can be compensated by not giving super good magical armour. I am a bit unsure if the starting level is too high though... Should they all be one point lower? Also these rules do not need to withstand free-for-all min-maxing, merely to be good enough to be used in a home game in a controlled environment without causing serious bugs or issues.

Thoughts?

 

[Fanaelialae]

So I've been working on this setting where the most advanced civilisations are on early bronze age tech-level and a lot of the world is basically at the late stone age. So reflect this I want to make armour less necessary, but still not remove it completely. The basic idea is lessen the AC increase that armour gives, but let characters to add half of their proficiency bonus (rounded down) to their AC.

So light armour is basically gone. Or it at least provides no benefit unless magical. This means that casters and light armour users both use the 'unarmoured' column of the table. This benefits casters a bit, so I might compensate by removing Mage Armour spell. It is a boring tax spell anyway. Now you don't have it but your standard AC is better. I also changed how Unarmoured Armoured Defence Class Feature works to be more consistent with these rules.

+++
(The table also only contains useful armour, I didn't want armours who were just objectively worse in every way except cheaper. So now there should be some benefits and drawbacks in every armour.)

Light/no Armour
Unarmoured	Free	11+ ½ prof + dex mod
(Unarmoured Armoured Defence)	(Class Feature)	11+ prof + dex mod
Medium Armour
Leather Armour	Cheap	13+ ½ prof + dex mod (max2)
Composite Armour*	Kinda cheap	14+ ½ prof + dex mod (max2)	disadvantage
Heavy Armour
Scale Armour	A bit expensive	16+ ½ prof	disadvantage
War Panoply**	Crazy expensive	17+ ½ prof	disadvantage	Speed -5

* This is basically a leather armour reinforced with some bones, bronze bits etc.
** This is a heavy bronze plate armour like Dendra Panoply (though maybe quite not so goofy looking.)

Shields work as normal.
+++

So does this terribly break anything? I know ACs scale now a bit while they otherwise wouldn't, but maybe two points across twenty levels is not so big of a deal? Especially as that can be compensated by not giving super good magical armour. I am a bit unsure if the starting level is too high though... Should they all be one point lower? Also these rules do not need to withstand free-for-all min-maxing, merely to be good enough to be used in a home game in a controlled environment without causing serious bugs or issues.

Thoughts?

These values are lower than what would typically be available to low level characters. Low level characters are more reliant on AC for survival (whereas high level characters can expect to get hit frequently, but have the hit points to soak the damage).

Therefore, this change is a significant nerf to low level characters, particularly front-liners. However, it's impact will subside as characters gain levels.

 

[Crimson Longinus]

These values are lower than what would typically be available to low level characters. Low level characters are more reliant on AC for survival (whereas high level characters can expect to get hit frequently, but have the hit points to soak the damage).

As a result, this change is a significant nerf to low level characters, particularly front-liners.

What? How are they lower? They are not lower... They are same for lower levels and higher past eighth level...

 

[Fanaelialae]

What? How are they lower? They are not lower... They are same for lower levels and higher past eighth level...

Mea culpa. I glanced over it too quickly.

That said, depending on affordability, some of the eliminated options (like a chain mail equivalent which is a decent cheap option for a starting heavy armor user) could be problematic. Particularly for a starting character.

Also, I wouldn't have a speed penalty on War Panoply armor. 1 AC for -5 speed is a bad trade off. Heavy armor users need to get in the thick of it quickly, so a speed penalty is a heavy price. I would suggest a minimum Strength instead.

 

[Crimson Longinus]

That said, depending on affordability, some of the eliminated options (like a chain mail equivalent which is a decent cheap option for a starting heavy armor user) could be problematic. Particularly for a starting character.

I eliminated all 'cheap crap' options that get replaced after a level or two. I guess you could start with anything except the war panoply if you had the proficiency.

Also, I wouldn't have a speed penalty on War Panoply armor. 1 AC for -5 speed is a bad trade off. Heavy armor users need to get in the thick of it quickly, so a speed penalty is a heavy price. I would suggest a minimum Strength instead.

Hmm. Perhaps. But I basically wanted there to be a trade-off for each armour. I'm not sure that going from 30 to 25 is that crippling and if someone feels that it is then they can use the scale.

 

[Fanaelialae]

Keep in mind that the game doesn't assume magical armor, so there's no need to scale AC over time the way you're doing.

Your approach doesn't really remove the need for amor for most characters, because armor is still vastly better in most cases. The only characters for whom armor is less necessary are light armor users, for whom armor has been eliminated.

An alternative approach might be to grant all classes and unarmored AC based on their armor proficiency.

Something like:
None == 10 + Dex
Light == 12 + Dex
Med == 13 + Dex
Hvy == 14 + Dex

In this case unarmored is preferable for characters who have a high enough Dex to benefit from it. Of course, some would argue that Dex is already an excessively good stat and doesn't need to be improved.

 

[Crimson Longinus]

Keep in mind that the game doesn't assume magical armor, so there's no need to scale AC over time the way you're doing.

Your approach doesn't really remove the need for amor for most characters, because armor is still vastly better in most cases. The only characters for whom armor is less necessary are light armor users, for whom armor has been eliminated.

An alternative approach might be to grant all classes and unarmored AC based on their armor proficiency.

Something like:
None == 10 + Dex
Light == 12 + Dex
Med == 13 + Dex
Hvy == 14 + Dex

In this case unarmored is preferable for characters who have a high enough Dex to benefit from it. Of course, some would argue that Dex is already an excessively good stat and doesn't need to be improved.

There certainly is an easier ways to mathematically get the result I want and get closer to the assumed math. But I want the system to be 'system aesthetically pleasing' and I don't feel that just arbitrarily assigning each class a flat score is that. Like if a game designer was writing a game from scratch it is unlikely that they would come up with such a solution. (This is a bit hard to explain.)

Characters who might prefer to use armour but are caught without it are in less severe disadvantage. And as 'light armour' is basically replaced with 'no armour' so this also means that for high dex medium armour users going without armour might be a valid option. Overall this reduces the amount armours worn and makes them less essential whilst not eliminating them completely.

 

[GMMichael]

Looks to me like light and medium armor are worthless, compared to the Unarmored Armored Defence. I'd just say that any metal armors grant attackers criticals on 19 and 20. Done and done.

Or remove the book's heavy armors and reskin the medium armors as bronze-type armor. No rule change needed.

 

[Oofta]

Personally? I would just replace armor with fantasy armor. Plate mail is replaced by turtle or ankheg shell armor. Maybe throw in some quests to get that shell armor.

Lot simpler, you don't have to futz with math. But I would also want to limit some of the spells, locks don't really make sense and many of the weapons.

I guess my point is that I don't see a reason to make anything more than cosmetic changes to armor if you aren't also going to redo all the other systems.

EDIT: ninja'd by @DMMike it will also depend on level of technology you have.

 

[Crimson Longinus]

Looks to me like light and medium armor are worthless, compared to the Unarmored Armored Defence.

'Unarmoured Defence' is the Monk and Barbarian class feature so, yeah it is supposed to be better.

Or remove the book's heavy armors and reskin the medium armors as bronze-type armor. No rule change needed.

That would still mean that people would wear light or medium armour instead of running around in a loincloth to stab a sabre-tooth tiger with their bone spear.