A common complaint about D&D combat is that you don’t really move around much during it. Two characters will get into melee range with one another and then takes turns punching each other until one of them falls down. Then the winner will go find another melee friend to trade blows with. Whereas in source material, fights are fluid. They move, people swing on chandeliers and jump on tables and such.
Most attempts to emulate this in D&D aren’t very effective. One approach has been to add in combat stunts, some specific maneuvers that benefit from mobility. 4e went all-in on this with each class having tons of powers which often required them to move or benefited from moving or the like. As anyone who follows this blog regularly (these people do not exist) knows, I find 4e interminably boring, so it will come as no surprise when I say that this didn’t really work. Ignoring mostly unrelated issues of fights being incredibly wrong and what exactly your character is doing to get a mechanical effect frequently being unclear, movement wasn’t at all spontaneous nor was it all that frequent. Now and again 4e characters would use a power that required or benefited from moving and they would do so, but this does not emulate the constantly shifting melee that you see in movies or even partake in during a LARP or similar. 4e also had a lot of attacks that moved their targets around, which isn’t really how the source material fights work at all. It’s really rare that someone is shoved or terrified into retreating across the room, but it’s ubiquitous for a character to move about of their own volition.
Indeed, in the source material you would be hard pressed to find one character who, for one full period of six seconds of fighting (actual fighting, not including cutaways to other characters observing or talking about the fight), did not move around. When you do find a character like this, odds are excellent you have either found a character who is generally not very mobile or who is fighting in cramped quarters. The hallway fight in Daredevil, for example, takes place across maybe five squares, and quite a bit of movement there happens because someone was forcibly shoved or else because Daredevil is moving from one set of mooks to another – but that’s because it takes place in a hallway, and there is little room to move. The scene where Aragorn and Gimli defend the gate of Helm’s Deep from the uruk-hai has them mostly stationary, but that’s because it’s a narrow walkway (given that there’s two of them, anyway), they are boxed in on all sides by the enemy, and the entire purpose is to keep the uruk-hai away from a door which they therefore need to stay nearby. The fight between Daredevil and his ninja nemesis in the same season and the fight at Amon Hen in the previous movie take place in more open areas and both of them move their combatants all over the place. In 4e, despite having tons of different powers, most attacks didn’t require you to move, nor did they move other creatures. It’s the opposite of what we’re looking for (although still a step in the right direction from the standard), with most fights being fairly stationary and occasionally things get highly mobile.
Another solution is to have vaguely defined combat stunts, where you can describe your character doing something awesome, roll Acrobatics, and if you succeed, you get some bonus to your attack or damage as determined by the GM. This encourages roleplaying out attacks and that’s great, while also encouraging players to think about how their character would fight by referencing their skill list and looking for relevant skills to help them and that’s also great. It does not make the fight a whole lot more mobile, however. Characters are unlikely to shift squares when they wall jump off a nearby pillar to get gravity on their side while slicing at an orc. That’s a cool move and all, but it still takes place within a single five foot square. Occasionally a stunt might require moving squares, but not usually. The structure of a stunt discourages it, because you’re still nailed to the paradigm of walking up to a bad guy and stabbing him until he runs out of HP and dies. Performing a stunt helps you stab him harder and/or more, but you’re already right next to your target so it’s actually bad for you if you move around.
Both of these attempted solutions – neither of which are really effective, though the second one does have some other benefits – concentrate on the attack, and that’s a mistake. The attacker doesn’t really want to move around that much. If it’s your turn and you’re in a good position to attack, you don’t want to move. Anything that moves you is a drawback that has to be weighed against other benefits, and in those source material fights it’s very rare that you see someone pull out an attack with so much momentum that it carries them straight past an enemy they’d like to remain next to. Usually such an attack will absolutely splatter the first guy in line and likely a few more mooks as well, and if not getting away from the opponent while also putting them on the defensive so they can’t pursue is usually the point. The attacker almost never wants to get further away from his target and the attacker is almost never compelled to do so in order to use some sort of super attack. It’s the defender who runs around all over the place, and the attacker is pursuing.
So, the paradigm you actually want to be in is one in which dodging is not only possible but ubiquitous, and in which dodging pushes you a square away from the attacker and the attacker is able to immediately pursue if they like. For example, an attack always counts as a critical hit, but the defender can take a five foot step in any direction away from the attacker to turn it back into a regular hit. The attacker swings their weapon at the defender, but if the defender retreats from the blow, they can turn a direct hit into a nick. If the attack is just a regular critical hit, then the defender doesn’t get to do this, the attack hits them directly before they can do anything about it. Similarly, if the defender cannot retreat because all three squares opposite the attacker are occupied, they must take the critical hit, hence the phrase “backed into a corner” or “back against the wall.” The attacker can pursue the defender immediately by taking a five foot step of their own.
We’ve only scratched the surface of the problem so far, though. Being an excellent swordsman and having multiple attacks gives you extremely deterministic control over the flow of a fight, and while good swordsmanship should obviously provide an advantage, it should be more chaotic and less reliable.
Also, with the current system having good armor is bizarrely helpful to controlling the tempo of a fight. If you have high AC, you don’t get hit and don’t need to retreat, but that’s not how hardly any of the armors in the game actually worked. Having leather armor didn’t allow you to absorb a strike to the chest 10% of the time without even feeling it. What it did was allow you to take glancing blows without harm, and the stronger the armor the more direct a blow it could absorb. If you roll with an attack, chainmail will prevent you from getting cut up, but if you’re taken off guard and the attack is a direct hit, chainmail might keep your organs on your inside but it’s not going to change the fact that you just had eight pounds of metal slammed into your body. It’s basically like being hit by a baseball bat, and while that’s better than being hit with a sword, you will definitely have the wind knocked out of you and may end up with a broken rib, both things that will stun you for long enough that the other guy can finish you off by slicing at whatever part of your body isn’t armored.
So chainmail and any other non-plate armor shouldn’t make you less likely to need to retreat, it should just make you less likely to take damage when you do. This means that armor is better represented as damage reduction, not armor class, and DEX alone should control AC. The problem is, every edition of D&D is balanced around armor providing AC, not DR, and having a change that deep is unlikely to just happen to work out. If you’re willing to gamble your game on it, go ahead and try it. Just convert the AC bonus of armor to a DR bonus instead and see what happens. Come and tell me how it went afterwards. It might work out.
Plate armor, by the way, totally can just stand there and take sword blows right to the cuirass and have the force dispersed across rigid plates until only the most incredibly strong foes can slice you to death. Killing a plate armored foe required knocking them to the ground and either impaling them by leaning into a stabbing weapon with your body weight or else stabbing them through their visor. The idea that having good armor makes you hard to hit makes the most sense for plate armor, which actually shrinks the target area that can be effectively hit completely, so you’re effectively attacking a smaller target, which means you need to be more accurate to succeed. Unless, of course, you’re firing a longbow at an enemy fifty feet away from you, in which case you’re going to punch straight through that plate armor like it was papier-mache. So plate armor should have plenty of DR, and if you really want to be accurate it should also provide resistance to cutting damage, but not to bludgeoning or piercing. This makes it basically a tank to swords but more vulnerable to arrows and hammers.
All of this plate armor nonsense is a bit of a tangent to the main point, though, which is making more mobile combats, not more historically accurate combats. What matters is that heavier armor shouldn’t allow you to totally ignore attacks without jumping out of the way. It should allow you to take less damage than you otherwise would have, and if you are jumping out of the way, it might even reduce the damage to zero. Armor provides DR, AC works entirely based off of DEX, and you take less damage when retreating, hopefully little enough that your armor will absorb all or at least most of it. If you’re forced to take that damage on the chin because you can’t retreat, your armor is much less likely to save you.
What about parrying, though? High DEX characters can duck and weave around attacks without retreating (as represented by their high AC), but a Fighter doesn’t need high DEX to be a brilliant swordsman with lots of attacks in one round all of which are very accurate. It’s kind of odd that being strong makes you just as accurate as being nimble, but it’s how the system works, and a Fighter who attacks both rapidly and accurately shouldn’t suddenly be clumsy on the defensive. Instead of retreating, a defender should be able to parry, making an attack roll of their own against an enemy attack roll. If the defender’s attack roll beats the attacker’s, then the attack is parried and has no effect. The defender can parry with a shield, in which case they get the shield’s bonus to their attack roll. I’m pretty confident that this isn’t balanced with 5e’s rules at all. Parries will be way too frequent. Also, we’ll need another name for that Battle Master maneuver, which does something completely different (and it’s not like parrying is a super special combat technique, it’s one of the first things you teach someone in any melee weapon).
Ultimately, this is because I’ve built up to a very different combat paradigm from D&D 5e’s, and the system math would need a total overhaul to keep up with it. However, one way to at least partially mitigate the issue is to control the number of parries and retreats available in a round. A parry takes up your reaction for the round. A retreat does not take up your reaction, but you can only retreat a number of times equal to your DEX bonus to AC per round. If you’re a lightly armored character with high DEX, you can retreat 25 feet across the entire room in a single round, mitigating damage from five different attacks. If you’re wearing plate armor, you can’t retreat at all. You can parry once, and you have to rely on your tank armor to absorb the rest.
Parries and retreats make the combat much more mobile (and also make armor more intuitive to new players), but unfortunately they probably can’t be plugged into 5e (or any other edition) without a total redesign of the combat math. I haven’t run the numbers myself (this article is already late so I really don’t have time to sit down and do the math for several hours), but I suspect that these changes would do terrible, terrible things to game balance. They really need to be the kind of thing that you start with and build the rest of the combat engine around. Maybe I’ll put something like this into Dark Lord or Dinosaur Riding Barbarians.