Friday, July 31, 2009

[Article] Parrying, Dodging & Blocking

An oft lamented aspect of Dungeons & Dragons is that as characters advance in level they become better at attacking, but not at defending. Occasionally it is contended that this aspect is represented by increased hit points, and that their loss partially represents the gradual erosion of defences due to fatigue. This might be a sustainable point of view if hit points were easily replenished without recourse to magic, but they are not. A recovery rate of one or two hit points per day of rest is not particularly suggestive of fatigue. In the Chain Mail man to man melee system, the ability to parry is a function of weapon class; a combatant has the ability to parry so long as his weapon is of a class no more than one above that of his opponent. The parry takes the form of imposing a −2 penalty to hit in most cases, but if the difference between weapon classes is eight or more it becomes only a −1 penalty. In any case an attack must be given up for a parry to take effect, though a character may have up to three attacks if his weapon has a sufficiently lower class than that of his opponent.

Whilst these Chain Mail rules could be used with Original Dungeons & Dragons, an additional rule was introduced in the Greyhawk supplement, to the effect that fighters could use their dexterity to attempt to “dodge or parry opponents' attacks”; for every point above fourteen, they would impose a −1 penalty to hit on attacks against them. This is obviously similar in conception to the protection afforded by a shield. By contrast, the Blackmoor supplement took a different tack with the monk class. Prohibited from wearing armour, the monk received a defensive bonus expressed as armour class that increased as he gained in experience levels. However, more significant was his ability to parry or dodge missile attacks (even magic missile) by means of a successful saving throw. This was a paradigm shift conceptually from what had gone before, introducing a second die roll unrelated to the attack roll and capable of negating all damage. This defensive mechanism took no account of the fighting ability of the attacker, only the experience level of the defender.

The defensive capabilities of the monk made the transition to Advanced Dungeons & Dragons relatively unscathed, and the ability of the fighter to use his dexterity to defend himself was extended to all combatants. The parrying rules from Chain Mail, though, were incorporated only partially, so that a character could impose a penalty on enemy attacks equal to his strength bonus at the expense of making any attacks that round. This was obviously of little use to a character with a strength less than seventeen. The cavalier class was introduced in Dragon #72, able to parry “more effectively” so that all of his bonuses to hit could be used as a penalty against enemy attacks. This class could also make a parry against a second opponent using his shield, which imposed a penalty equal to its defensive value, but prevented it from being used for the rest of the round. This was a long way from the original concept as articulated in Chain Mail, being over reliant on high attribute scores, as well as bonuses from magical weapons and armour.

With the second edition of Advanced Dungeons & Dragons, an optional parrying rule was introduced as a function of level and class. A character could give up his chance at action for the round to gain a bonus to armour class against melee attacks equal to half his level, with an additional +1 for fighters. That same year, the Complete Fighter’s Handbook suggested a second option, where a character could give up an attack to attempt a parry. This required the character to hit his opponent’s armour class to negate the attack, inadvisedly implying that the armour class of a combatant was reflective of his fighting ability. When the rule was revised and incorporated into Combat & Tactics, this premise was wisely discarded and a fixed armour class set as a level of difficulty. This should all sound familiar to players of War Hammer, where a character can similarly trade his attacks for parries, needing to roll under his weapon skill to reduce damage by 1d6 in first edition; in second edition all damage is negated on a successful parry.

A noticeable problem with Advanced Dungeons & Dragons second edition is its approach to fighting with two weapons. Even though it limits the number of secondary attacks to only ever one, this still effectively doubles the attacks available to most characters. Coupled with the potential to eliminate the normal penalties through high attributes or proficiency slots, and weighed against the relatively small benefits of using a shield, it is often viewed as something of a rules exploitation. This was probably why Gygax earlier specified that the “secondary weapon does not act as a shield or parrying device in any event.” By contrast, War Hammer avoids this problem by not granting any additional attacks from secondary weapons; they are useful primarily because they provide bonuses to parry rolls. In developing Astonishing Swordsmen & Sorcerers of Hyperborea, we have had to consider carefully how any combat actions we suggest might interact with multiple attacks in order to ensure that no undue or unintended advantages are unexpectedly revealed during play.

Regardless of whether a parry, dodge, or block takes the form of an attack penalty or a saving throw, the action must be traded against a commensurate disadvantage. A simple trade off of fighting ability against armour class is a fairly straightforward approach, amounting to –X to hit in return for –Y to be hit. However, the benefit of this trade depends on the number of attacks the character is exposed to in a round. The obvious recourse is to trade against the number of attacks the character has available, but this may unduly enhance the benefits of a secondary weapon. Since a shield lowers effective armour class by one, a secondary weapon ought to be of no greater advantage. Other methods to consider for modelling a parry, dodge, or block include opposed rolls, parallel armour class, and forced rerolls. In those cases, shields would have to be treated exactly like secondary weapons, meaning attack penalties for the primary weapon. I have made available a selection of possibilities for your perusal here and a compilation of the rules mentioned above here.


Jay said...

Great post! BTW, where did you find that pic? It's awesome!

Matthew James Stanham said...

I am glad that you found it of interest, Jay!

I believe that particular illustration is by Angus McBride, more famous for his historical Osprey work than his fantasy stuff, but he did a number of Lord of the Rings pieces.

The first time I encountered that one was as one of the collectable "Middle Earth" cards for the "block" event. If you do a Google Image search for "Angus McBride" you will find many, many such pieces.

Reina said...

On secondary weaponry:
I believe both major ideas to be somewhat correct (between 2nd edition and warhammer, though, 2nd Edition's is clearly skewed wrong to me).
The second weapon is usually no more than a convenient, small, parry tool in many forms, such as rapier and dagger. However, heavy pick + a short blade, katana + ko-dachi, or double katars (though awkward that), all had offensive reasons for their secondary weapon.

Instead, offering a second attack only on closing in that has a good chance of hitting at the loss of not having a suitable primary attack, or, offering a secondary parry option but not both, modable; This is a route worth exploring, in my opinion.

omne51 said...

Some of your concerns involve the fact that you don't want to make a secondary weapon better than a shield for defense.

Why not incorporate the Player's Option Shield proficiency rules, which increase the Shield's defensive capabilities (and makes it more realistic, in my opinion)?

Matthew James Stanham said...

Reina: That does sound interesting.

Omne51: A lot of people feel that the shield rules in AD&D are not a sufficient representation of its effectiveness. In my opinion, they are wrong. When you are talking full mail armour only reducing the to-hit chance by 25%, then 5% for a shield is more than enough, especially when one considers that dexterity encompasses parrying with the shield as much as dodging or parrying with a weapon.

The bottom line is that I think the Player' Option shield specialisation rules are both unbalancing and not a very good representation of the protection a shield affords in the general abstraction of the combat system.

omne51 said...

I know you are very learned where ancient weapons are concerned, but I must disagree.

In my research, the shield is vastly underrepresented as a defensive tool, and is probably more valuable than most armor.

Matthew James Stanham said...

Well, a lot of folks feel that way, but I do not think that they are seeing the full picture and abstraction. A shield is a good defensive implement, but its effectiveness is often overestimated, especially in the context of D&D where people tend to swing from one perceived extreme to another.

The reality is that shields were often not employed because it was more (or just as) advantageous to use a two-handed weapon. For that to ever be the case you either have to radically change the way D&D works or be satisfied with the trade-off, which in my estimation is not too incredible anyway.

The most useful function of the shield is in warding off missiles, and even in cultures that almost never used hand-held shields (such as Japan) or in the late period medieval west free-standing shields, or something of that sort, were utilised in prolonged exchanges (especially during sieges).

There is a lot of debate about the effectiveness of armour, to be sure, but I certainly subscribe to the school of thought that sees it as very effective, which will obviously colour my opinion. The most overlooked consideration, though, is that an unarmed character in AD&D (second edition) is considered worse than prone (+4 bonus to hit and damage), but by wielding a weapon or shield this is negated. Thus a shield could be said to be in fact a +5 AC.