Alternate Accuracy Mechanics

[tomBitonti]

Automatic damage feels like "sanding down" of the fine detail of combat. You could achieve this in 3E/4E by replacing to hit and damage rolls with a simple removal of hit points. That is, a first actor declares an intent to harm a second actor. The first actor exerts effort to harm the second actor. The second actor exerts effort to resist harm. Both actors lose a tangible resource (a measure of their effort). The difference in effort turns into harm (possibly reversed, if the second actor resisted the first well enough).

If that is the framework that you are working with, what the actors are left with are their budget of effort for their action, and what the system still has room for is the variability of the result. That could be automatic (barbarians always swing wildly) or under player control (do I spend some time aiming, or shoot wildly and hope for a hit?)

I could see accuracy worked into the system as a difference between actor choices. Shooting wildly (seems to) work better against an opponent who runs a random dodge pattern. Careful aim works better against an opponent who take a static guarded posture.

Thx!

TomB

 

[slobster]

I've got an idea. I'll explain the system, then do a cursory statistical analysis and pro/con list, and then list off a few random thoughts to finish things up.

The basic idea is that you roll a d20 along with your damage dice every time you attack. Every attack hits automatically and deals damage. The d20 is a randomizing agent (it can represent chance or the opponent's defense or your ability to land a decisive blow, or some gestalt of the three) that determines whether you get a critical hit, a critical fumble, or a normal hit.

You compare the result you got on your damage dice to the result of the d20 roll. If your damage dice result meets or exceeds the result on the d20, you score a critical hit. If not, you score a normal hit. If you roll a 20 on the d20 and a 1 on the damage dice, you suffer a critical fumble.

So let's look at a quick probability analysis of this method. You can use any dice, and I'll look at the chances to score a critical hit with the "common" damage dice d4, d6, d8, d10, d12, and d20. It's a rare game that rolls d20 for damage, but I included it for completeness.

dice . . . . avg damage . . . . crit chance . . . . fumble chance
d4 . . . . . . . . 2.5 . . . . . . . . . . 12.5% . . . . . . . . . 1.25%
d6 . . . . . . . . 3.5 . . . . . . . . . . 17.5% . . . . . . . . . 0.83%
d8 . . . . . . . . 4.5 . . . . . . . . . . 22.5% . . . . . . . . . 0.63%
d10 . . . . . . . 5.5 . . . . . . . . . . 27.5% . . . . . . . . . 0.50%
d12 . . . . . . . 6.5 . . . . . . . . . . 32.5% . . . . . . . . . 0.42%
d20 . . . . . . . 10.5 . . . . . . . . . . 52.5% . . . . . . . . . 0.25%

Pros
* You can use any damage dice in any combination you wish (though it's smoothest when the total you can roll on damage is below 20; higher than that and things get funky)
* Higher damage dice have a better chance of scoring a critical hit, and a lower chance of rolling a fumble
* You can add static modifiers to your damage dice to increase the damage dealt without affecting the chance that you crit (just don't use the modifiers when comparing to the number you rolled on your d20)

Cons
* You have to roll an extra die, and comparing the numbers takes time
* Rolling high on the d20 is bad, which may be counter-intuitive
* Crits happen quite often (depending on your preferences and the results of scoring a crit, this may belong in the "pro" section)
* Fumbles are exceedingly rare (again, you may consider this a good thing) and happen when you roll a natural 20, which may be counter-intuitive

Now I haven't gone into what happens when you score a critical hit or suffer a fumble. That discussion properly belongs in the design of the game engine and not the analysis of the dice design that I do here, though obviously the needs and shape of the game system will affect which dice system is ideal. You could add damage to crits, deal wounds (if you have an hp/wounds system), or earn tokens that can be spent to inflict conditions or whatever.

If you think the dice system is interesting, I'd be glad to continue the discussion after I know a little more about the system you are making. There are also a lot of little changes you could make to adjust the frequency of crits and fumbles, if you want to explore that.

 

[mmadsen]

I agree that making every turn count is a good thing, but I wouldn't make every swing a hit to achieve that. It's certainly not realistic, and it doesn't feel right in action fiction, either.

After playing Knights of the Old Republic, the Star Wars video game based on the d20 tabletop game, Shamus Young wrote about redefining hits and hit points in a way that would make sense for duels with deadly weapons:

The first step is to throw away the hit point bar. We don’t need it. If someone gets hit, they die. Instead of hit points, we have “Focus”. You can call this whatever you like: Balance, focus, concentration, defense, ki, zen, or whatever label you think best conveys to the player “this is your ability to defend yourself”. When your foe takes a swing at you, your character will deflect the blow with their weapon, and you will lose a bit of Focus. If your Focus runs out, you will fail to stop their attack and they will fatally run you through.

With this small change we now have a system that works just like the old hit-point system, except the game will no longer show the combatants hacking away at each others’ midsections until one of them falls over. The gameplay will work the same, but look a lot more reasonable.

But we can do even better…

The Stamina Meter
Boxing games have this. Every time you take a swing, your stamina goes down a bit. You can take between five and ten swings before this meter is empty. At that point you need to stop and recover for a few seconds, and your foe will have the opportunity to strike back. If you continue to attack, your exhaustion will cause your swings to be slow and clumsy. Your foe will be able to fend off your blows easily, and you will not damage their Focus.

Furthermore, pressing the attack when you are drained will damage your stamina, meaning your meter will either fill more slowly or not fill all the way, thus reducing the number of useful attacks you can make in the future. This is a gradual thing: Occasionally taking an extra swing is no big deal, but relentlessly abusing your arm will seriously weaken you and put you at a great disadvantage.​

Read the whole thing.

 

[Celebrim]

[MENTION=1645]mmadsen[/MENTION]: I have often considered adopting the hit point mechanic to give players 'hit points' related to every attribute - focus points, stamina points, reputation points, will points, etc. The main reason I haven't is the extreme effort involved in redoing the system, and the fear that the resulting system - while perhaps more capable of simulating a wide variaty of situations - would end up being far too complex and involve far too much bookkeeping in actual play.

It might work well for a video game where all that book keeping can be handled by the machine, but whether its the best solution for a PnP game is another matter.

But, even in terms of Star Wars, I'm inclined to disagree that 'focus' is perfectly good simulation. The Star Wars characters do seem to have hit points of some sort. The heroes at least do take 'flesh wounds' from blasters which are invariably lethal to storm troopers and other mooks. Vader actually takes a superficial hit from a light saber 'deflected by his armor', shortly before maiming Luke with a non-lethal 'critical hit'. These situations imply some sort of mechanic that governs the seriousness of the hit, as well as a mechanic that prevents hits.

 

[mmadsen]

I have often considered adopting the hit point mechanic to give players 'hit points' related to every attribute - focus points, stamina points, reputation points, will points, etc.

I agree that multiple different kinds of hit points could easily overcomplicate things. I think the key insight is that a fight should involve intangible points that don't reflect hits at all. We shouldn't track health so much as momentum or balance.

Simply pressing the attack might "damage" the target in this intangible sense, and retreating might "heal" such damage.

When you run out of mojo, attacks start hitting and doing true physical damage.

This is subtly different from the wounds/vitality system of d20 Star Wars, because it doesn't necessarily use the same to-hit and damage mechanics as physical attacks. Bonuses and penalties come from terrain, etc., not the size and sharpness of the weapons involved.