Active defenses as modifiers
 

I'm working on a hack to speed up combat and reduce the number of rolls. I'm inspired by what happened with Chronicles of Darkness, where they took a similar algorithm to GURPS (roll to attack, roll to defend, roll for damage, roll for soak) and boiled it down into one roll.

Now one roll might be a bit optimistic, for now I am looking at removing the active defense roll by making it a modifier to the attack.

My overall idea is to leave everything as it is, including the defender choosing the form of defense, or being able to reduce the opponent's defense via feint etc, but the attacker takes the defender's active defense score, divides it by a number, and applies it to their attack roll.

Yesterday I experimented with this number being 3, and rounding down. This seemed to have the desired effect of making combat quicker, but defenses still mattered. For all out defense, I used the sum of two defense scores as a modifier.

I wonder if other people have tried something similar to this, and with what success? I am aware that it causes some issues in the system e.g. actions which happen after a successful parry, but I think these things can be resolved.

I'm also not trying to say this is the way everyone should do it, if you like defense rolls who am I to yuck your yum, but as an experiment I'm trying to see how to speed up GURPS combat while leaving the original framework in place.

In a similar vein, one idea I had for feint was simply to compare the weapon skill of the attacker with the skill, DX etc of the defender and have the attack modifier be the difference between the two, if it is in the attacker's favour.

Re: Active defenses as modifiers
 

Maybe making the calculation is quicker, but it isn't obvious to me on the face of it. How long does it take to recalculate the modifier vs. how long to make the additional roll?
If speed is the issue, replacing 2 second task A with 2+ second task B might not have the desired effect.
If it is indeed quicker, how much time did you save?

Re: Active defenses as modifiers
 

I'd imagine you'd just write what your Defense Modifier is on your sheet ahead of time, then when someone attacks you just see if their MoS was enough to soak the penalty. So if you have Block 15, Parry 12, and Dodge 9, you just note that you impose a -5 to hit with a Block, -4 with a Parry, and -3 with a Dodge.

But the proposed system gives radically different hit probabilities compared to RAW. Assuming equal skill and further assuming no bonuses (Combat Reflexes, shields, etc), you're typically looking at around a 45% chance of successfully hitting the foe (succeed on attack, fail on defense) if you're using Deceptive Attack (or even Telegraphic Attack at low skill) to get your skill to around 13-14, which generally gives the highest overall hit probability. With the proposed system, you need to look at multiples of 6 (when the defense bonus changes). At skill 12, that's Parry 9 and thus -3 to hit; that gives a 37.5% chance of actually hitting, which may be close enough to 45% to work alright. But at skill 18, Parry 12 gives only a -4 to attack; that gives a 91% chance of actually hitting. At skill 24, Parry 15 gives a -5; you're at the cap of ~98% chance of actually hitting, and any higher skill is above that. Looking at the in-betweens, skill 13 gives an overall hit probability of 50% (close enough to 45%), 14 is 62.5% (too high from here on), 15 is 74%, 16 is 84%, 17 and 18 are each 91%, 19 is 95%, and 20+ are all 98%.

EDIT: An alternative option that may come closer to the RAW distribution would be to subtract your skill (or 2xBasic Speed for Dodge) from 10 to determine the penalty (which will mean a bonus against those with skill below 10, but that kinda represents using Telegraphic Attack against those). For defense modifiers, like from Shields, Enhanced Defenses, etc, you'd double them and apply as a further penalty (which also means you could have higher resolution - instead of DB 1, DB 2, and DB 3 shields, you could have -1, -2, -3, -4, -5, and -6 shields; meanwhile Combat Reflexes would probably only impose a -1 and you could have half-levels of Enhanced Defense available that only give -1 each). This matches pretty well for equal skill (50% chance instead of 45%), but will deviate the further apart the characters' effective skills are.

Re: Active defenses as modifiers
 

my big problem with this is: as a PC it takes away all agency I have as a player.
I should be able to adjust my defenses, use retreat or FP as I see fit & then rely on MY luck/roll to determine if I get hurt or not. I don't like that it's all on some other guy's roll.

Also, does you modifier let me choose to retreat or fp defense?

Re: Active defenses as modifiers
 

I don't see why it wouldn't- you declare them when the opponent attempts his attack roll rather than after it succeeds, and they penalize his attack roll rather than benefiting your defense roll.

In principle, I see no reason why such a system could not be made to work, but, for me personally, getting to roll for a parry or dodge (rather than having my skill at parrying or dodging abstractly reduce the opponent's chance to hit) is part of the attraction of GURPS, and I doubt I'm the only one with such feelings.

Re: Active defenses as modifiers
 

You may wish to check out an article from Roleplayer 23 (included in Compendium II):

Very Basic Melee Combat: Really Simple Shortcuts for Really Quick Battles by Steffan O'Sullivan. Yes, this means it was for Third Edition, but even with the changes between Third Edition (Revised) and Fourth Edition, I think it still works. The very first section of this article is titled Attack, Defense, Damage and is about handling all three with a single roll... or rather, a Quick Contest between fighters. So when two fighters clash, each combat turn is another Quick Contest, and the results determine which (if either of them) were successfully attacked, and how much damage was done.

I'm uncertain as to whether I should go into more detail; the article isn't overly long, but covers five different shortcuts; the section I'm mentioning is only the first, and only three paragraphs long. Half the length is from the third paragraph, an example of combat using these rules!

...

Total tangent, but it is kind of funny if you read it in Compendium II like I am; the side bar article from the previous few pages is The Fight's Over Already? Optional Rules for Pacing Combat. I really did love how much information was crammed into ye olde Compendiums :D

Re: Active defenses as modifiers
 

I came into the hobby in the late 70s with a _lot_ of combat in Chivalry & Sorcery 1e which worked a lot like this. It was nice when you were the more skilled fighter that it was more difficult to be parried or dodged.

I found Gurps with its' "flat" defenses to be somewhat annoying. Some of this may have been before I appreciated the ability of crits on attacks to be always successful.

Runequest 2 may have had some of this "A successful defense always beats a successful attack" problem.

Re: Active defenses as modifiers
 

In Runequest 2 at least a successful attack could damage the parrying weapon or possibly smash through a shield.

Rolemaster also works like the OP is looking at. One of the potential issues with doing this in GURPS is that it makes anything that reduces your hit chance very bad. It also makes deceptive attacks worse than useless, but this might no be of concern if skills aren't expected to get over twenty or so.

By the way, this also applies to doing quick contests - anything that might reduce your margin of success has to return huge dividends, so wise players will make very few targeted attacks, etc.

Re: Active defenses as modifiers
 

The main incentive for doing something like this is streamlining: GURPS combat with can turn into quite a slog of failed attacks (this is particularly common when using shields) so cutting down on the number of rolls will cut speed things up. There's other ways of accomplishing the same thing, though (changing combat to a quick contest, for example).

Re: Active defenses as modifiers
 

I've seen the slogfest argument before, and taken it seriously, but every time I look into it more deeply I come across a failure to utilize terrain and tactics to change the dynamics of the fight. I get that the default attack-defend-damage loop can get boring and crit fishing is dull, but suggest that we generally do have good options to make fights interesting without actually changing the rules.