Except you do not play heroic fantasy in Whfrpg, you fight often enough you will die.
You can use Armor DR in 5e. We have used it for over 5 years now and it works really well for us.You can't use Armour as DR as a number. It doesn't work due to scaling issues. Either it becomes increasingly less useful as you level up or it scales and you quickly reach a point where PCs are completely invulnerable to less threats.
To even have a stab at it you would need to really go through all the monsters and rewrite them with those issues in mind. (For one thing, DR means that single high damamge attacks becomes much more threatening when compared to single attacks - and inversely Fighters get screwed more than rogues if fighter monsters with DR). One thing to remember is that D20 Conan was never intended to work with regular 3.X monsters.
If you want Armour as DR you need to work with the concept of Resistance (because half damage scales at all levels and against all kinds of attacks).
We fix this by only having DR come into effect on a confirmed critical (or when HP = 0). Otherwise a hit just removes HP and doesn't seriously wound you (reducing your bloodied hit points). This system makes crits more exciting (and potential dangerous) and heavy armor more important. Also, since it only comes into effect on crits (and @ 0) it doesn't have much overhead.The problem with DR, other than being a lot of overhead, is that it totally nerfs some monsters while having minimal impact on others. Something that relies on a bunch of low impact hits may mean their attacks have no impact while heavy hitters that rely on one or a few attacks are relatively unaffected.
I don't know how you fix that with the way that D&D works. As far as realism, someone in full plate should be pretty impervious to most normal attacks. To take out someone in high quality plate armor you had to grapple and overwhelm to the point you could pry open their armor and stab them in the face. They were the tanks of their day. But that doesn't necessarily make for fun game.
We were able to add DR to 5e rather simply, with very minimal changes (no changes to HP or damage, maintain armor AC, a simple method to determine armor DR and wound points). I've talked about it a lot on these forums, but no one else seems to like. or hasn't decided to try, it. But our group loves it and that is all I really care about!I've tried to tinker with alternate armour rules in D&D, but it's a huge amount of work. Once you get into adjusting damage and hit points for everything you're really getting into new system territory.
I'd prefer to play something that has DR baked in, like witcher. It uses fairly static HP and damage and therefore can use armour as DR much more effectively.
Adding two modifiers to your defense score makes more sense as it gets the numbers closer to the base assumptions of 5e. I wonder how spells like shield and bless would figure into this type of defense?I honestly like this a lot... Might use it as a Houserule for the Project Chronicle setting.
Dodge: 10+Dex+Wis
Parry: 10+Str+Con
Block: 10+Shield+Int
Most of the time players choose which defense type to use, but some attacks (Like spells that would normally target AC) go after a specific defense type.
That'll probably result in 3 different levels of AC, Really. Strongfighters will always try to parry, Lightfighters will always try to dodge. And smart characters will try to keep a shield handy...
Personally I like it. Helps reinforce Sword and Sorcery character identity.
Talking with my players, there's a suggestion to do 10+Stat+Prof, instead. Or maybe 8+Stat+Prof.Adding two modifiers to your defense score makes more sense as it gets the numbers closer to the base assumptions of 5e. I wonder how spells like shield and bless would figure into this type of defense?
It's true...My issue with armor as dr is it tends to unbalance weapons, which while realistic also removes aspects of versatility. Throwing a dagger doesn’t work very well when dr drops the damage to nigh 0