Double Defense (AoD) and Feint

[DouglasCole]

Originally Posted by the_matrix_walker

Dropping skill under 16 is foolhardy. The issue isn't fear of critical failure, it's loss of the odds for critical success and bypassing the enemy's ability to defend.

And while dublindog's imageshack calculations and forum posts (including off list) have text that states the importance of that extended critical hit rule, the images themselves are no longer viewable. But I also recall that dropping attack to 12 was not universally the best solution; in fact, the highest odds of a hit depend greatly on your own and your foe's effective skill. It's not "drop it to X under all circumstances," but I do remember that "the spreadsheet" strongly supported not nerfing your chances to crit except in extreme circumstances.

Heck, now I'm curious. I'm going to go do the math, and post it on my blog. Some of the previous charts that I did find online I find hard to read.

[The Benj]

I apologise if I've hurt anyone's feelings by seeming dismissive of DF. I certainly bear no ill will for the genre, I just think its over the top cinematic nature means it's not helpful for appraisal of Feints in realistic baseline. That's all.

[dripton]

Originally Posted by DouglasCole

And while dublindog's imageshack calculations and forum posts (including off list) have text that states the importance of that extended critical hit rule, the images themselves are no longer viewable. But I also recall that dropping attack to 12 was not universally the best solution; in fact, the highest odds of a hit depend greatly on your own and your foe's effective skill. It's not "drop it to X under all circumstances," but I do remember that "the spreadsheet" strongly supported not nerfing your chances to crit except in extreme circumstances.

Heck, now I'm curious. I'm going to go do the math, and post it on my blog. Some of the previous charts that I did find online I find hard to read.

I've got a simple spreadsheet for this.

A few sample points:

Attacker skill 16, defense 10
total damage chance 53.7% at 16, 57.4% at 14, 55.3% at 12, 42.1% at 10

Attacker skill 18, defense 12
total damage chance 42.6% at 16, 46.3% at 14, 47% at 12, 37.5% at 10

Attacker skill 20, defense 14
total damage chance 32.3% at 16, 35.2% at 14, 38% at 12, 32% at 10

Attacker skill 26, defense 18 (Peter's earlier example)
total damage chance 23.7% at 16, 24.9% at 14, 28.9% at 12, 25.9% at 10

"Deceptive attack your skill down to around 12" really is a good rule of thumb, if you're not going to actually calculate the odds at the gaming table. (Which you can't really do anyway if you don't know your opponent's defense roll.)

Of course, leaving your skill at 16 has a few benefits versus bringing it down to 12. One, more chance at a roll on the critical hit table. (The fact that critical hits negate the defense roll are already factored into the above total damage chances, but the possible extra damage from a critical hit [if your campaign uses those rules] are not.) Second, no critical miss on a 17. Third, you're more likely to force a defense roll (as opposed to just missing), which can use up your opponent's parries, blocks, retreats, fatigue points for extra effort, etc. and also give them a chance to roll a critical failure.

But, most of the time, I'd rather have about a 5% higher chance of doing damage. That's much larger than the 1.4% extra chance of a critical miss.

[Peter V. Dell'Orto]

Originally Posted by dripton

This is an undue level of risk aversion.

Heh, no.

Originally Posted by dripton

If dropping your weapon is the worst thing that can happen, because your enemies basically can't hurt you, then, sure, keep your skill at 16.

Dropping your weapon was one example of the effects of a critical miss. It isn't the whole of it. The Critical Miss Table has complete examples, I won't quote it.

Originally Posted by dripton

However, if your enemies are actually a threat, then the odds of them hitting you greatly exceed the odds of you rolling exactly a 17.

Actually, I don't think that's true.

Originally Posted by dripton

And by reducing your odds of knocking them out of the fight this turn, you're giving them more chances to hit you. Against an opponent with decent defenses, Deceptive Attacking your skill down to 12 or so is almost always better than keeping it at 16 out of fear of a critical failure.

Yes the downside of a critical failure can be very high - the downside of using Feint plus an attack at 16-17 (the skill level my players aim for) is much smaller, and the upside is high.

Originally Posted by dripton

Now, there are some cases where hitting but being defended is more useful than flat-out missing. For example, if multiple combatants are ganging up on a tough opponent, then making sure you hit (and soak up his parry, his block, his retreat, his acrobatic dodge, etc., leaving just his lower basic dodge for your allies) can be smart. But in a one-on-one fight, the spreadsheet doesn't lie. The math trumps your anecdotal opinion.

Ah - in a "one on one fight."

The last one on one fight we had in my campaign was a duel, back in session
41. The PC lost, but he had a run of bad luck vs. my run of extremely good luck on behalf of the enemy.

Your match may trump my anecdotal opinion, but my anecdotes in this particular case are a so-far 48 session combat heavy campaign of multiple-fighter combats, not a featureless plain duel. I trust those anecdotes and the very real consequences of missing or higher rates of critical failure in those situations than the math of a featureless plain one-on-one duel.

We recognize that staying at 16+ whenever possible has costs in terms of overall hit rate, but we play in a game where staying at 16+ minimizes the incredibly fight-changing downsides of an untimely critical, and almost never have one-on-one fights. The upside of a hit via almost-maximized Deceptive Attack is not as large as the downside of a critical failure on a confused and lethal multiple combatant battlefield.

[Peter V. Dell'Orto]

Originally Posted by The Benj

I apologise if I've hurt anyone's feelings by seeming dismissive of DF. I certainly bear no ill will for the genre, I just think its over the top cinematic nature means it's not helpful for appraisal of Feints in realistic baseline. That's all.

My comments on that particular case weren't meant as an appraisal of Feints in "realistic" combats. Or all combats. I maintain they are useful whenever your skill exceeds that of your opponent, and yet you aren't able to reliably penetrate his defenses just by using DA, and/or there are non-trivial costs to attacking repeatedly (Parry U weapon, weapons that need re-readying). Those, in a nutshell, are cases where Feinting is a potentially useful tactic. The actual raw numbers aren't quite as critical, although they aren't unimportant. It's the skill edge with a cost for attacking that's the core of it, though.

[DouglasCole]

Originally Posted by dripton

I've got a simple spreadsheet for this.

My numbers and yours differ by a slight amount, which I suspect is based on how we do our formula. Mine is

P(Crit) + (1-P(Crit))* Probability of a Hit * Probability of Failed Defense

The "optimum" for any given deceptive attack is dependent on both the attacker's skill and perhaps more importantly down to the defender's skill.

The purely mathematical answer is actually darn complicated. Looking at previous posts, "get the sum of effective skill + foe's defenses to 22-25" is the best rule of thumb. It's definitely not as simple as "get it down to 12," though.

At attack skills of 10-13, the rule of thumb is "don't." Or rather, only DA by -2 to hit if you're facing someone either way better than you, or someone with heavy DB who's using a lot of retreats, and thus has effective defenses of 12+.

At skill 14, you DA (-2 to hit) against a foe with defenses greater than about 10. So Joe Average with a shield. But honestly "don't" is a better rule of thumb here too.

At 16, you DA for -2 to hit against average foes not leveraging high DB or retreats. DA down to 12 up until your foes have Defense 15+, then don't DA at all (you're crit fishing in that case).

Jumping to 20, you DA down to 16 against mookish fighters (defense up to 10), then probably to 14 to defense 15 or so, then again, no DA from about 18+. There's a narrow window where down to 10-12 is a winner.

At Skill-23, for mighty DF goodness, the optima are worth stating explicitly

DA down to net skill 17 if your foe's defenses are up to 8. Dropping down to 15 instead won't hurt you. Dropping to 13 will.

Dropping to 15 is the best strategy up to foe's defenses of 12, and it's less than 5% worse than dropping to 13 up to foe's defenses of about 15.

Drop to 13 is the best strategy from defenses of 13 through 16, and it's not awful until you start crit-fishing from defense-20 and higher.

Note that at Skill-23, you're looking at Parry-14 with no shield, no magic, and no retreat. Add in +2 DB for a shield, +1 for a retreating parry, and +1 for armor magic and you're Parry-18 without working that hard.

And if you're Attack-23 vs Defense-18, you will definitely want to drop your effective skill down to 17 one way or another (could be shooting for the neck or vitals or a crippling leg or something, or a DA). The difference between 17 (13.42 chance to hit) and 11 (technically the "best" option at 17.8% chance) is 4% extra chance to hit, with less chance for you to crit, your foe gets a defense roll at all (which means he can use things like Riposte on YOU, plus you've more than tripled an admittedly low chance of your own critical fail) might not be that much relative to the cost of a bad roll.

It's even more complicated than i thought - though my rule in play tends to be "go down to 15-16" and my Warrior Saint's usual Axe/Mace skill is about 20. With his Righteous Fury on, it's often 24.

So given you don't often know your foe's defenses, "down to 16" is less than 5% different than the optimal strategy until my foe's defenses are 14+, and with A/M-24 that extends to about 16+.

Beyond that, I distract him while the airborne Gargoyle goes for a back-shot with no defense possible.

[Mailanka]

Originally Posted by The Benj

I apologise if I've hurt anyone's feelings by seeming dismissive of DF. I certainly bear no ill will for the genre, I just think its over the top cinematic nature means it's not helpful for appraisal of Feints in realistic baseline. That's all.

I don't really see what a realistic baseline has to do with anything. GURPS is a game-system, not a reality-simulator. Some people will run 50 point horror games, yes, and some people will run 500 point martial arts games. There are lots of characters who will have amazingly high weapon skill: high DX supers, cinematic martial artists, cinematic swashbucklers, cinematic super-spies, DF swashbucklers and knights, super-advanced AI warriors, psionic space-heroes, and so on. On more reasonable scales, highly trained martial artists with a focus on the Feint maneuver might also have very high skill.

A question like "What's the use of Feint?" is fundamentally a system question. Not "What is the point of zigging when he thought I would zag," as that could be represented by just about anything in the system, but "What is the point of using the Feint maneuver?" The answer to that is agnostic of setting.

[Tomsdad]

Originally Posted by Peter V. Dell'Orto

You can do that already - Beats affect a single defense for everyone, and check the Teamwork and Pack Tactics Perks for Feint (and other things.)

No I know, that's why I mentioned in the first half of the sentence giving them a slight extra bonus for established team tactics that rely on a specific chain of events, like a combo that involves more than one person.

At some point I might codify it and allow them to put points in a combination of technique that two or more can use as chain of set events/actions, that will leverage an even greater bonus.

I only mentioned it here because we were talking about getting players to state intentions and act quickly, this works well here because it means two of my players have already formed a plan and state it pretty much as a combined intention, which speed up play.

TBH I only referenced in in passing so it probably wasn't that clear!

[T.K.]

Larger/simpler scales always make something easier to be perceived or understood.
This is very simple line of thinking/methodology used in research, math, engineering, physics and alike.

I'd imagine only a very simple minded and straightforward person would have trouble interpreting and extrapolating bigger numbers (skill level) for the same system (Feint) to lower levels/numbers/situations...

Both a cinematic skill-40 Fighter and a mundane but very good skill-18 Fighter have to make the same decision when it comes to min-max effectiveness: Do I DA beyond effective skill 16, thus loosing crit, or cap at 16 to keep maximum crit range and reduce critical failure range as well?

It doesn't matter that the cinematic warrior will have to DA for more than -24 and the mundane will for only more than -2 to reach this decision making situation; the decision will be as important for both.

On the math discussion currently presented so far, I might be wrong but from what I could understand people are not considering that the extra Crit from keeping skill 16 completely negates the defense of the target...is that the case?

The biggest gain from going 14>16 skill isn't the ~9% increase in chance to hit but the fact that the defender simply can't defend at all (except for Luck or similar).

[dripton]

Originally Posted by DouglasCole

My numbers and yours differ by a slight amount, which I suspect is based on how we do our formula. Mine is

P(Crit) + (1-P(Crit))* Probability of a Hit * Probability of Failed Defense

Yep, we're using different formulas.

My formula (which I think follows directly from the GURPS mechanics) is:

P(Crit) + P(non-critical hit) * P(failed defense)

(for example, with attack 16 vs. defense 10, it's P(6-) + P(7-16) * P(11+)

which can also be phrased (to make it look more like yours) as:

P(Crit) + (P(Hit) - P(Crit)) * P(failed defense)

I think your formula gives answers a couple of percent high.