Question about the maths behind attack roll and defense rolls

[Rupert]

Originally Posted by Agent

I believe the 3rd edition compendium offered various options. It included doing deceptive attacks functionally automatically (instead of a quick contest though maybe that was there too) where every 2 points of success over skill gave a -1 to defend. It had an option for increasing critical success with high skill as well.

I used that in a 3e campaign. What I found was that, 1) it was very hard for a less-skilled opponent to ever land a blow, and conversely it was very hard for them to avoid blows, and 2) people never did anything that would lower their hit chance, ever, and that AoA for +4 to hit was way too low-risk unless your opponent had strong armour (because you would almost never miss, and your opponent would very likely not defend, and thus never get to strike back).

Essentially it takes all the options in GURPS' combat system and says "Don't bother - these are a waste of time.".

[Lupo]

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 game would be boring :)

I don't like simple opposed rolls for attacks and parries.

First of all, this mechanic tends to blur a poorly executed/failed attack and a good, but parried, attack.
The difference is quite important: in the latter case, the defender's weapon might break, or he might incur in penalties for repeated defenses.

Moreover, choosing to perform a Deceptive attack (and how much Deceptively) is now an important part of GURPS tactics. Fighters can "push the envelope" risking difficult attacks which impose a huge penalty, or they can fight more conservatively and hope their opponent's defense fails.
Having all attacks automatically "as Deceptive as possible" would eliminate choice and risk.

=

I'll also point out that, if you make Attack/Defense a single opposed roll, defenses become considerably more difficult. They become almost impossible, actually (two fighters of equal skill will rarely be able to defend against each other). So if you want to follow that road, you should probably raise defenses a bit.

[D10]

What about Feint guys ? Doesnt that work for what you want ?

[Anaraxes]

I misspoke when I said "Pyramid" earlier. The title of the periodical that accompanied GURPS in the late 80s that I had in mind was "Roleplayer". I checked through the ones I had handy, but I didn't find the article I seem to remember. So perhaps it was just Usenet. Though my Roleplayer #3 was missing... but I think that's a bit early for this sort of rule anyway.