Question about the maths behind attack roll and defense rolls

[gjc8]

Originally Posted by SolemnGolem

From a mathematical standpoint, what's the effect of this? If the designers had decided to make it an opposed roll, and applied Attacker's margin of success as a penalty to Defender's defense roll, how would the game be different?

The current system has the deceptive attack mechanic to make it effectively into a contest. The difference is that the attack must commit to a penalty before hand. This is a significant disadvantage.

It also gives an relative advantage to attackers who know what the defender's skill is.

[laguna]

Originally Posted by gjc8

The current system has the deceptive attack mechanic to make it effectively into a contest. The difference is that the attack must commit to a penalty before hand. This is a significant disadvantage.

It also gives an relative advantage to attackers who know what the defender's skill is.

hadn't noticed that.

huh.

[gjc8]

Originally Posted by laguna

hadn't noticed that.

huh.

It's a key feature of the system. 3e lacked such a system by default, and suffered exactly the problem you pointed out.

The books, unfortunately, don't really explain how important it is.

[laguna]

Originally Posted by gjc8

It's a key feature of the system. 3e lacked such a system by default, and suffered exactly the problem you pointed out.

The books, unfortunately, don't really explain how important it is.

yeah, it had been my intention to expand the crit numbers beyond 6 (for skill 16) to 7 and beyond so that two master swordsmen would chop each other to pieces with crits instead of endless parries.

now i'm thinking that won't be necessary.

[Landwalker]

Originally Posted by laguna

yeah, it had been my intention to expand the crit numbers beyond 6 (for skill 16) to 7 and beyond so that two master swordsmen would chop each other to pieces with crits instead of endless parries.

now i'm thinking that won't be necessary.

Why would you expect two master swordsmen to rapidly dismember each other instead of to have a long, drawn-out duel?

[laguna]

Originally Posted by Landwalker

Why would you expect two master swordsmen to rapidly dismember each other instead of to have a long, drawn-out duel?

i wouldn't expect them to, but under my previous understanding of the rules, I would PREFER they chop each other up quickly as opposed to having a net 5% chance to hit per turn.

[Landwalker]

Originally Posted by laguna

i wouldn't expect them to, but under my previous understanding of the rules, I would PREFER they chop each other up quickly as opposed to having a net 5% chance to hit per turn.

So, as I understand it, you want them to dismember each other because it's quicker and more convenient for you, as opposed to adhering to realistic expectations?

(I'm not saying there's anything wrong with wanting convenience, I'm just verifying what your position is.)

And in any case, even if you bump them up to Skill 26, the 5% hit chance is hyperbolic.

Skill 26 means Parry 16 (and what the heck, let's give them Combat Reflexes and Enhanced Parry 1, for a Parry of 18).

The attacker can take a -16/-8 Deceptive Attack, dropping both the attack and the parry to Effective Skill 10, and there would be a 25% chance of successfully striking the defender.

A -14/-7 deceptive attack: 27.8%

-12/-6: 24.4%

So the -14/-7 is the optimal point, giving you a 27.8% chance of success per turn.

If you adhere to the "one-second turn" idea, then that means that there will be about one strike per four seconds per swordsman. It's not unreasonable, then, that such an encounter might last 15 seconds or less.

That's also disregarding other attack options. If the attacker uses a Committed Attack (Determined), he can get up to 37.1% with a -16/-8 Deceptive Attack, but he'll be in a bad spot defending afterwards.

And then of course there are Feints (and Beats and Ruses), dozens of techniques, rapid strikes, etc.

[SolemnGolem]

Originally Posted by Landwalker

Why would you expect two master swordsmen to rapidly dismember each other instead of to have a long, drawn-out duel?

This could be quite accurate though. Skill improves, but in GURPS your hit points don't. And as a fighter becomes more and more effective at doing high damage, the human biology doesn't keep pace with the ability to absorb damage (no matter what DnD and its 100+ HP characters would have you believe).

This may not apply to all fighting styles, but I'd say it's an accurate model for several. In fencing matches it's been my experience and observation that mid-level fencers give the most "entertaining" matches. The high-level fencers strike so quickly that one or the other has blown through to their target in a handful of seconds. (Granted, this is under competition-safety conditions where the round is over upon a successful hit - but I can only imagine the real-life swordfight experience wouldn't be much different. Once you start taking damage, you're into the vicious cycle of injuries hampering performance, leading to more injuries.)

[DouglasCole]

Originally Posted by Landwalker

Why would you expect two master swordsmen to rapidly dismember each other instead of to have a long, drawn-out duel?

When I've seen two master martial artists fight, I don't notice that bouts go on longer. If anything, they're shorter than novice v novice fights (the novices spend a lot of time moving around doing utterly ineffective things).

Turning my observations to GURPS, what I've seen is that good practitioners basically throw Deceptive attacks that bring their hit chance down to a net of 13-14 as a matter of course (after footing, which is almost always good, and hit location and use of Techniques are accounted for). You throw the bestest blow you can without flailing, and you do it every time it matters.

The only time you don't do this is when you're using lower skill than you have in order to teach...

[jacobmuller]

Originally Posted by Landwalker

Why would you expect two master swordsmen to rapidly dismember each other instead of to have a long, drawn-out duel?

Possibly because he was intending to extend the Crit Success beyond 6. A Crit on your attack allows no defence, therefore, higher Crit chances for Masters would mean shorter fights than for novices. Tempting.