- The basic Damage Field. It costs 5 REA to activate and while it's up, every time you are struck in HTH combat it hits your attacker. Usually it does this at a negative modifier (because it's attacking their fist instead of, like, their face ... unless they hit you with their face or something). However, if they grab or grapple you they get hit for more damage--also: if you are grabbing or grappling them, you can pulse for 5 REA to do damage with it.
- The "Ranged Damage Field." This could just be Medium Reach spikes (which can hit people trying to sword-attack you) or even some kind of "return fire system" which would do ranged attacks at people shooting at you.
- Block-Damage-Field. Out of Street Fighter II (for example). You crackle with electricity when you block--and only if you successfully block does the opponent take damage.
- Partial Coverage Damage Field: Like a coat of spines or something--but they can hit around it the same way they hit around armor.
These are "scary" because: (a) it's hard to tell how often they'll be used. They cost 0 REA to use so if you have a good damage field and are attacked by a bunch of goblins or something you might kill them all before you even get to act! Secondly because there are some questions and variations around whether / how you can attack with the damage field outside of pulsing it: if you are covered with fire and punch with "flame hands" does your target take an extra damage field hit or not? (Answer: if you buy it that way).
So it was complex--but we can simulate it. So: complete success, eh?
Not So Easy
I've written on this topic before but I'll revisit it here because I'm doing it for Chi Martial Arts. When there's a power that only effects 1/4 of our target characters in the simulator (The Herd) it gets "under reported." The basic damage field, which I tested, shows something like a +10% advantage. That looked pretty minimal to me. But, of course, I knew why: when I counted only the empty-hand targets it was more like +45% Percent Chance of Victory. That's huge.
So what to do?
Who Has This Stuff?
It's true that having a no-range damage field wouldn't be worth that much in a wild-west campaign where everyone is armed and they all want to shoot you. Sure, it'd take the bar-room brawls up to the next level but even there, even the densest NPC would stop trying to break a chair over your back and start shooting ... 'cause he'd have a gun. They all do.
No, the answer to "Who has a Damage Field" comes in about two flavors: Super heroes and martial artists. And we can sub-class Super Heroes to "those who plan to fight hand-to-hand." In short, the thinking is that the kinds of people who will buy Damage Fields are the ones that will most leverage it. That means it should be costed higher than it tests in the simulator--especially if you think it'll be held by offensive grapplers who will use their high grapples to overcome the low-damage-modifier issue.
So What'd I Do?
The first thing was "balance" the attack just for unarmed punch damage. That was pretty severe though--the Damage Field guy was losing badly to everyone else. So I walked it back up a little, aiming for a moderate advantage if the person with the damage field is fighting a pure hand-to-hand person and substantial but not huge disadvantage.
A HTH-Impact Attack is 16 (L1), 10(L+). The multiplier for making it a damage field is .625 making the damage-field equivalent (which can also be used to strike) 11, 6.