Realistic Combat that's Simple(ish)

[Mercurius]

By realistic, I primarily mean differentiating what D&D calls AC into its two components: dodge/parry and damage reduction.

Or to put it another way, a more realistic version of D&D would have to-hit vs. an opponent's ability to dodge, parry, or otherwise evade being actually hit, and also damage reduction as the result of armor, toughness of skin/hide, and magic.

(This was inspired by re-watching Excalibur for maybe the 20th time, and the early scene when someone smites Uther in his full plate, and blood pours out...easy to hit, some damage reduction but still blood as he was prone and it might have been a crit)

To-hit vs AC is a useful simplification, but has always irked me - mostly because it is a sacred cow, and wouldn't be all that hard to add realism without too much complexity. It means that a slow and full-plate-armored tank and a fast, leather-wearing duelist have similar AC, when really we should have:

Tank: easy to hit, hard to cause damage​

Duelist: hard to hit, easy to cause damage​

I mean, it would be simple enough to implement in D&D without too much fuss:

Defense: Base Number (10? 5?) + Dex Mod + some combination of Proficiency Bonus + Weapon Bonus (magic and/or parry bonus for specific weapons) + Class Features + Possible Feats. Sort of like AC, but replacing armor with bonuses. I started with 10 for the base, but on further thought considered that it maybe should be 5, with more bonuses than AC making up the difference (e.g. Prof), so more "swingy" than AC.​

Damage Reduction: A number from (probably) 0-10 for conventional armor that reduces damage from melee weapons, or the "naked to full plate" spectrum, with 1 being clothing, maybe 3 being leather, 5 being chain, 7-8 partial plate, 10 full plate; over 10 for some monsters (e.g. dragons, tarrasque, etc). Presumably crits would bypass DR, or reduce it.​

Now of course this would have be balanced and the kinks were worked out to find the right numbers, but with a bit of work it would provide what I'm suggesting within the context of D&D.

So my question: Which RPGs--especially fantasy RPGs--already do this well, and in a way that isn't overly complex? Preferably still requiring just one role. Please give a brief explanation of how it works.

 

[soviet]

Rolemaster solved this circa 1980.

Both combatants have an Offensive Bonus (OB) resulting from their skill, strength, positional advantage, etc. At the start of the round each combatant decides how much of their OB they use to attack and how much they hold back as a Defensive Bonus (DB) that subtracts from incoming attacks.

Some editions have a similar decision point regarding Initiative where you can act quickly at -20, act normally at +0, or act slowly at +10.

When you attack someone you roll d100, add your OB and other bonuses, and subtract their DB and other penalties.

The real innovation is that you compare your result on a table. Each weapon has its own table (like broadswords and shortswords and scimitars and daggers are all different full-page tables). There are 20 Armour Types, from AT1 (nothing) tthrough leathers and chain to AT20 full plate. Each one is a separate column on the table. The results on the table determine whether it's a hit, how much hit point damage it causes, and what kind of critical table you roll on. Rolemaster characters generally have a lot more hit points and it's the critical hit tables that create the deaths and maimings.

What this means is that some armour types (like AT1) have more total misses (you are better able to dodge) but when you do get hit, it might be 20 hit points damage and a nasty crit. If you're in leather you are a bit easier to hit but the armour soaks up some of the damage so you lose less hit points and get reduced crit levels. If you're in chain or plate you are even easier to hit again but a lot more attacks that would have been nasty crits against AT1 are reduced to just hit point damage or lesser crit effects.

These tables are different for each weapon so slashing weapons might be even worse against plate while piercing weapons are even better against leather.

It seems very complex, and has a reputation for being complex, but as long as you can do a bit of addition I would say it's less complex than most modern editions of D&D. The tables do a lot of the heavy lifting.

 

[payn]

Traveller uses armor as DR, or soak score when determining damage. You can also take actions to raise the target number of the roll. For example, if a player take cover it makes the target higher, or if they decide to dodge it also changes the target number. So, it remains a single roll but each character can do things to improve either hitting or dodging attacks in a game round.

 

[Theory of Games]

GURPS has a similar system, but according to many people it isn't simple so I won't waste the space.

Th Arcanum (originally Bard Games) had a simpler system:

1. Attacker rolls to hit TN 11+ by rolling 1d20 + DEX modifier + any circumstance modifiers or magic bonuses
2. If the attack hits, the defender rolls 1d20 + DEX modifier to dodge with a result of 11+ meaning the attack missed. Parrying requires the defender to make an attack roll that equals or exceeds the attacker's roll in order to succeed.
3. If the dodge fails, the attacker rolls damage. The target's armor lowers the damage based on whatever type of armor it is

The Arcanum began as rules variants for AD&D1e but turned into its own game with rules that were IMO simpler but also more more dynamic than AD&D. If you can find it (I hunted down a copy on NobleKnightGames) it's worth a look, especially if you like old-school rules.

There's also a newer 30th Anniversary edition from ZiLa Games that adds and changes rules but tries to maintain the feel of the original game.

 

[RenleyRenfield]

...
So my question: Which RPGs--especially fantasy RPGs--already do this well, and in a way that isn't overly complex? Preferably still requiring just one role. Please give a brief explanation of how it works.

So I think Cypher does this =
And in a way that the Players always get to act, so no GM rolling vs GM garbage.

Example =

Cypher has 3 Pools

• Might
• Speed
• Intellect

pools tend to be 10 to 30 points each.

Pools represent your characters ability in both resistance and offense. How much you can take and how much you can exert.
Since getting smashed in the head also makes it harder to hit back, it makes sense they have both of these aspects of offense and defense.

Damage is a set value, so no rolls (or rarely are there rolls, some cases do).

So you get a TN, and roll 1d20 to hit. The TN is reduced by various things, skills, abilities, situations, equipment. And most importantly, spending Pool to apply extra effort.
The TN is set by the opposition's general threat level, could come from any number of narrative things that factor into a overall "this is how hard this thing is to fight".
Enemy special abilities if applicable (such as dodge or tough or parry or whatever) either alter the TN or alter the damage you deal.
No rolls, just values.

Player rolls once, (usually using Might pool) and deals set amount of damage, and enemy armor reduces that (Soak) by set amount.
So its just a matter of choosing effort and the enemy choosing applicable abilities.

When it comes time for the player character to get attacked. It is identical to above, but uses Speed (dexterity) pool to see how they avoid the harm.
GM states who is attacking and how much damage it does. Player rolls once to avoid. GM never rolls dice. So its nice that players feel like they are always "playing".

 

[dbm]

Many, many, RPGs do this. Arguably only D&D and its close relatives use the ‘roll versus AC’ model.

GURPS has this as mentioned. Savage Worlds does it with a similar rules weight to 5e when take as a whole. The target number to hit an enemy is derived from their fighting skill rating.

The best d20 system I have seen which does this is Conan d20 from Mongoose. It had dodge and parry scores for characters which were based on skill and stats. Armour was damage reduction. Mongoose Conan is an under appreciated gem in my opinion, for this and lots of other reasons.

 

[Reynard]

Body armor exists for the inevitability of getting hit, stabbed, shot, whatever. More importantly, it is designed with expectations in mind for what "getting hit" means. That is why armor has changed so much over time.

So if a fantasy world, armor is going to be a complex choice. If you are a knight or mercenary who is going to primarily fight other knights or mercenaries, you are going to go with some standard choices depending on the "era." But what if you are fighting wizards who regularly throw lightning or dragons that breath fire, or squamous monstrosities dripping with acid? From a game design standpoint, "realistic" damage reduction armor in a fantasy world is going to be a complex mess: think AD&Ds AC vs Armor Type dialed up to 11.

 

[Bill Zebub]

First, I really like how Dragonbane works:

• Dodge and Parry are two separate skills; depending on the opponent you can use either, one of them, or neither.
• When attacked, you can consume your turn to Dodge or Parry...if you haven't taken your turn yet (some exceptions). If you do, then on your turn you can't attack.
• Armor provides damage reduction.

 

[soviet]

First, I really like how Dragonbane works:

• Dodge and Parry are two separate skills; depending on the opponent you can use either, one of them, or neither.
• When attacked, you can consume your turn to Dodge or Parry...if you haven't taken your turn yet (some exceptions). If you do, then on your turn you can't attack.
• Armor provides damage reduction.

WFRP did all this in 1987

 

[Mercurius]

Rolemaster solved this circa 1980.

I said "simple."

It seems very complex, and has a reputation for being complex, but as long as you can do a bit of addition I would say it's less complex than most modern editions of D&D. The tables do a lot of the heavy lifting.

OK, fair enough...thought still a bit more complicated than I'd like, and I'm always a bit leery on "chart-dependence."