If 4d hits 50% of the time, is it ≈ 8d-24?

[RyanW]

Originally Posted by Raekai

So, is there a way to do something like that in GURPS (even if it would be too much trouble)? If every attack hits, it seems like you would modify damage based on the chance that the attack would hit (in addition to DR and such). Which is where I got 50% chance of 4d ≈ 8d-24.

The problem is you are moving the peak of the curve, which completely messes with the distribution. With 4d, about 50% of all results are between 12 and 16. 90% are between 9 and 19.

With 8d-24, the numbers skew much lower, even counting only the non-zero numbers. 50% of the non-zero results are between 2 and 6. 90% are less than 10.

[Anthony]

Originally Posted by RyanW

Also, very likely, "I'm bored because we have spent the last five minutes cross referencing the original damage, attack skill, and defense, and counting the resulting bucket of dice."

I have considered just reducing defenses. Under current RAW, two equal skill melee combatants start out at a maximum of 46% chance of hitting (12 vs 9, using deceptive attack as needed to turn the contest into that). If combat reflexes or retreat is involved, that drops to 37%, or 28% if both, and it gets even worse for shields or weapons with +3 retreat bonuses. By comparison, D&D has tried to normalize for around 70% hit chance.

If you delete the +3 for active defense (so it's just skill/2, or speed for dodge), hit chance maxes out at around 75% (16 vs 8 or 14 vs 7), and with combat reflexes and retreating it's still at around 57% (14 vs 9), 37% (12 vs 10) with combat reflexes and +3 retreat bonus.

[RyanW]

To be honest, I've never quite gotten the "I didn't do damage this turn. It was wasted" vibe.

I've seen fights in games that (translated to GURPS) spent a lot of time doing something like:

Fighter A, turn 1: Evaluate.
Fighter B, turn 1: Evaluate.
Fighter A, turn 2: Evaluate.
Fighter B, turn 2: Feint, fail.
Fighter A, turn 3: All-Out Defense.
Fighter B, turn 3: Step (back) and Wait (If opponent steps forward, Defensive Attack, Thrust for weapon arm)
Fighter A, turn 4: Evaluate.

[Anthony]

Originally Posted by RyanW

To be honest, I've never quite gotten the "I didn't do damage this turn. It was wasted" vibe.

The problem is that there's no real concept of progression. In real combat, an attack that doesn't land might still be setting up to get a benefit later (or, conversely, it could put you in a bad position), but that's not something RPGs generally emulate (there's oddities such as Lost Worlds).

[Varyon]

Here's something I think would work. Take effective skill (treat skill 3 - or lower if you allow a roll - as skill 4; maximum effective skill is 16) away from 20, and subtract this value from a 3d roll; this is your damage result. Subtract the same value from 18, and divide your maximum damage by this value; the result is your damage modifier. Multiply the damage result by the damage modifier to get basic damage, which is then modified as normal by DR, WM, etc to get Injury.

So, consider a character who does 4d damage. Maximum damage is 24. With skill 10, the player rolls 3d-10 and multiplies the result by 3 - 50% chance of 0 damage, and a maximum roll of 8 does 24 damage. With skill 8, this is instead 4*(3d-12), and a maximum roll of 6 does 24 damage. With skill 14, this is instead 2*(3d-6), and a maximum roll of 12 does 24 damage.

Note while the probability of doing damage remains the same as with an undefended attack under normal GURPS rules, and the maximum damage stays the same, the above system does skew things such that a character with high effective skill is more likely to roll high damage than a character with low effective skill, assuming both roll well enough to actually do damage.

[RyanW]

Originally Posted by Anthony

The problem is that there's no real concept of progression. In real combat, an attack that doesn't land might still be setting up to get a benefit later (or, conversely, it could put you in a bad position), but that's not something RPGs generally emulate (there's oddities such as Lost Worlds).

I might propose some sort of momentum mechanic. A barely missed attack (or barely made defense) gives the attacker some sort of short term boost that can be used to press advantage.

[RedMattis]

In anything but a 1v1 you generally care a lot about positioning. Trying to flank enemies without getting flanked.

You've also got a variety of tactics like using Extra-Effort for dodges while evaluating up a big bonus with the intention of performing a wicked All-out-Attack Feint+Attack with Mighty-Blow to cripple your opponents main-arm. This would be a very all-or-nothing tactic, but depending on the opponent it can be very effective.

Etc.

If you want to make combat more interesting I'd suggest just looking more at optional rules, especially from GURPS Martial Arts and GURPS Fantastic Dugeon Grappling.

[Plane]

Originally Posted by Raekai

I want every attack to hit, but I don't want every attack to do damage.

If the idea is to take out defense rolls to cut down on time, you could just treat it like a penalty to attack skill.

GURPS Ultra-Lite at http://www.warehouse23.com/products/SJG37-0032 does that: defenders don't roll, instead attackers just subtract half the defender's combat skill.

It sounds like maybe you want to further streamline by combining tohit+damage into a single roll?

This also kinda touches on the T-bone idea of narrow misses doing half damage, where striking accuracy places heavily into it, while near-misses can reduce damage.

Firstly if Ultra-Light doesn't go this far we should come up with a new term. Super is higher than Ultra in Audiology so maybe "Super-Lite"?

If the idea is that you want 0s to be as likely in your new system as a miss would be, you'd first figure out miss % using the Ultra-Lite rules (subtracting defenses to make it a single skill roll) and then convert...

But I'm wondering if there's some more convenient way to convert for less easy %s than 24. Some kind of shorthand.

Your approach appears to be "double the damage dice (4d>8d), then subtract the maximum (24) the non-doubled dice could roll"

I think what you're aiming for is that the maxiximum damage remains the same?

I would consider however that this throws off the AVERAGE damage being the same, which is more important. The average for 4d is 14 and the average for 8d is 28.

14 damage hitting 50% of the time is 7 damage per hit on average, while subtracting 24 from 28 results in 4 average damage per hit.

We would want this to work out to an average of 7 damage per hit somehow. I'm just not sure how we get there...

To get to 7 from a base roll of 8d (avg 14) means subtracting 7 (the avg of 2d)

So it seems like you're basically going to want to do is calculate the average of your dice, then add (double) your intial dice and subtract the average.

This unavoidably would make maximum damage higher though: 8d-7 can result in as much as 41 damage, unlike the max 24 you can get from 4d.

That's probably fine through since you're not able to roll critical hits anymore.

8d-7 can't result in 0 though so maybe we're not going far enough?

12d-14 perhaps? This would further up it to a maximum of 58 damage, but keep in mind that 24*3 actually makes 72 possible damage under the old rules on 4d with a x3 crit strike.

Basically every 2d would be replaced by 6d-7. Not sure about 1d increments or fixed number bonuses/penalties.

[Daigoro]

What happens to the bell curve with 4d12? Heretical, I know...

[Anthony]

Originally Posted by Daigoro

What happens to the bell curve with 4d12? Heretical, I know...

Standard deviation changes from ~3 to ~7.