Worlds of Design: Combat Methods

Is there an ideal combat method in an FRPG?

Picture courtesy of Pixabay.​

"He will win who knows when to fight and when not to fight." Sun Tzu

RPGs in many cases revolve around combat. Yet the player who understands Sun Tzu’s maxim knows that fighting is merely a means to an end, not an end in itself (though, I must admit, that also depends on the experience rules…).

Dependent vs. Independent Combat​

If you’re not familiar with these terms, watch my Independent and Dependent Combat video on YouTube.

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Independent Combat​

Independent Combat involves each side resolving their attacks without opposition. This is common in Dungeons & Dragons, where there’s an attack roll against a static number (usually Armor Class). A defense rating and obstacles are built into this challenge, but there is no variable opposed roll to determine if it’s successful.

Speaking of Armor Class, this is another abstraction that affects Independent Combat. In real life, armor is suited for very specific situations, not to be worn at all times—and thus an Independent Combat system has to accommodate for armor, Dexterity, resilience (sometimes referred to as Natural Armor for monsters) and other factors.

There are a lot of reasons why Independent Combat is used in games, but chiefly it’s a streamlined system, if not mechanically sophisticated. It scales well, because the defensive target number is static, and thus when a player attacks multiple opponents, it’s also easier to resolve.

Dependent Combat​

Dependent Combat involves a (sometimes opposed) dice roll to avoid the attack, depending on the skill of the target as well as on the armor. Note that including a target’s armor class or skill level in the resolution of the attack is not in itself Dependent, some action is required of the defender player. As a result, dependent combat is a bit more complex, and takes more time to roll.

In melee skirmishes this is sometimes called a “parry” system, which is how it worked in Palladium’s rules (Rifts being on example). Notably, monsters who have the ability to Parry in Dungeons & Dragons (like the gladiator) only add a boost to Armor Class, thereby keeping the game firmly in the realm of Independent Combat.

In computer video games, Independent/Dependent combat often happens behind the scenes, but it can matter a lot. Does the speed you hit the button or execute a maneuver help you do more damage or hit more often? Or is it a simple roll you can’t see to determine if you hit, based on your character’s skills and abilities?

There are a wide variety of mechanics that can cover the spectrum between one attacker rolling to hit (Independent), and two combatants opposing each other in real time (Dependent). I’ve seen at least one system that resolves where the attack lands on specific body parts in determining whether it actually does damage, and how much. More “realistic” perhaps, but also time-consuming. In the very simple RPG I designed to use with a board game, a successful hit does a set amount of damage, no dice roll for damage required. Less exciting, but quicker and simpler.

Low vs. High Standard Deviation​

Another consideration is whether hitting in combat is fairly predictable or “swingy.” That is, a low standard deviation vs. a high one. Some combat systems are quite realistically lethal (high damage per successful attack), which encourages people to avoid fighting. A high standard deviation in hit probability could amount to the same thing, though lethality has more to do with damage than hit probability.

Low standard deviation in the extreme would be deterministic combat, where there is no uncertainty - but that’s unlikely to be fun in an adventure setting. In my simple game, you don’t know if you’ll hit, but you know how much damage you’ll inflict if you do hit. (And you can build your character to inflict more damage per hit, as well as to have a higher hit probability.)

The higher the standard deviation, the more often characters will be hit in combat, and probably the more often they will die - though that also depends on the amount of damage per successful attack.

To Crit or Not to Crit​

Standard deviations affect combat in subtle and overt ways, including critical hits: can a single attack do (on average) a lot of damage, perhaps killing the target, or only a small amount? This is why the way a game handles (or even allows) critical hits can immensely impact the pace of combat. Critical hit systems may seem more realistic, but we have to ask how much fun they are in actual play. Most of these systems I see inflict extra damage (making the standard deviation of damage higher overall).

The one I devised and used for a while inflicted location damage, for example, “left arm becomes unusable until points inflicted are healed” or even “target cannot walk for a week!” I wanted to set up additional dilemmas for the players to face. I finally set it aside because it was extra work, and the injuries could change the adventure drastically in sometimes undesirable ways.

Role-playing games take many different approaches to combat, and all of them have a feel that creates a level of immersion or abstraction, determined in part by dice rolls, by the players themselves, and the opposition. How often a character can hit, if their attacks are against a static number or by an opposed roll, and the consequences of a hit can all significantly influence how your game works in actual play. If you’ve ever thought about designing your own game, I hope this has helped you find new ways of thinking about it.

Your Turn: Do you prefer Dependent or Independent styles of combat in your role-playing systems?

 

[Celebrim]

What I prefer is that the rules don't describe a complex piece of software that is apparently intended to run on wetware, yet the rules be broad enough that they don't radically fail in (too many or commonly occurring) edge cases. Ideally they should also be somewhat fun.

How you obtain that is less important, but in general it tends to involve few die rolls and static difficulties.

 

[Thomas Shey]

There can be plenty of modifiers, but they are used to pre calculate the combat bonuses. They only have to be recalculated when something changes like a weapon swap etc. Things like parry, dodge skills factored in to defense bonus

I'm referring to situational ones--attacking from above, cover, things of that nature.

 

[Bri]

I'm referring to situational ones--attacking from above, cover, things of that nature.

While you could, philosophically best to avoid.

Things like elevation and cover... What it really does is increase range. High ground advantage is not that it's easier to hit from above, but plain you can hit them and they can't hit you. You can move downhill much faster than they can move uphill. You can see them but they can't see you.
You can move and attack. They can only move (uphill) or attack. Assuming you're not completely surrounded, by time enemy gets to top of hill, you could have escaped opposite direction and be a mile away before they figured out you escaped...

This kinda play to me is more interesting, and allows simpler combat mechanics.

I showed one example of Slow and how it could change bonuses during combat, but kinda bad example. Could just reduce number of actions/attacks per round, and not adjust combat probability

...

Also note. The folks that like these systems usually like to play multiple characters at a time, so you're looking for a system as simple as possible to allow that.

There's a tradeoff. The more characters you play at a time, the simpler the rules should be.

 

[Thomas Shey]

While you could, philosophically best to avoid.

Yeah, can't agree with that. Reduces tactical choices too much.

Things like elevation and cover... What it really does is increase range.

Can't agree. Elevation is even beneficial in melee because it makes it easier to hit the upper body and head. And cover is beneficial when its too close for modifications of range to matter.

There's a tradeoff. The more characters you play at a time, the simpler the rules should be.

If its too many character to manage halfway detailed character, its too many characters far as I'm concerned. I've managed a bunch of opponents as a GM in fairly detailed systems, so I don't see it as prohibitive.