I've just started running a low-powered Dark Champions© campaign, and for some reason I've had an overwhelming demand for sectional armor. To be completely frank, HERO just doesn't really cover that. Oh, sure there's the Activation Limitation (actually, I've even used it as a basis for this rule), but it just doesn't cut the chase.
So, without any farther ado, I present before you "The HERO System Sectional Defense Rule".
First of all, lets take a look at the Activation limitation. In this limitation, you limit your power by an Activation Roll, and the lower the roll is, the higher the limitation is, and hence the cheaper the power is. But, what the hell does "14-" mean? What is the actual chance of succeeding in such a roll? What is the difference between "14-" and "15-", and is it the same as the difference between "14-" and "13-"?
So, first of all, here is the table from the Activation Limitation (HERO System 5th Edition Revised Rulebook pg. 283), with two modifications. First, the original table only gives the limitation for rolls between "8-" and "15-", with "12-" being equivalent to "13-" for some reason, and I've continued it in both directions, from "3-" to "17-". Second, I've added the column "Chance of Success", which gives the chance of succeeding in the roll (in percentages). I've taken the liberty to slightly modify the values in order to keep the continuity of a -¼ difference between each roll, except the very low ones, for which I've added the nonstandard limitations of -1/8, –1/16 and –1/32. Also note that the Activation Roll itself is NOT used under this new rule, but is only given as a parameter you would find easier to refer to.
|Activation Roll||Limitation||Chance of Success|
Now consider the hit location table. What is the actual chance of hitting any location? (Assuming you hit in the first place, of course). The answer to that question is summarized in the following table.
|Roll||Location||Chance to Hit|
So, for instance the chance to hit the head (sections 3-5) is 0.46%+1.39%+2.78% = 4.63%.
To save you the time and effort, I did the math myself and put the results in the following table:
|Roll||Location||Chance to Hit|
Now, after we've got all of that number crunching, out of the way, the rule itself (finally!).
The rule itself is quite simple. First, find the chance to hit the location(s) you want the armor to protect. Then, find the limitation with the lowest chance of succeeding, rounded up (i.e., the closest limitation which isn't larger than the limitation you would get using the Activation Rolls rules).
For Endurance purposes, or any other purposes (such as Drains, Transfers or Dispels), consider the active cost as the active cost of the defense, divided by the limitation for the sectionalist. This is to simulate the fact that it takes less effort to create a force field around your torso than around your entire body. Note that if you build a defense that is made up of different sections (with different ratings), for all intents and purposes (such as Frameworks, Dispels and Suppresses), it is considered to be one power.
Let's take the character Nocturnal Knight (a dark, gothic Sir Lancelot wannabe). First of all he wants to purchase a Plate Mail Corselet, which he defines as an 8/8 Armor (base cost of 24) that protects locations 9-15. The chance to hit these locations is 11.57+12.50+12.50+11.57+9.72+6.94+4.63 = 69.43%. The closest to this percentage (without passing it) is 74.07%, which is a –¾ limitation, and is more-or-less equivalent to an Activation of 12-. So, the Corselet will cost 24/(1+¾) = 14 active points. He also takes the limitation OIF (-½), so the real cost would be 24/(1+¾+½) = 11 points.
Then, he wants to purchase Chain Mail Brassards and Leggings (6/6 Armor, locations 7-8 and 14-17). The chance to hit these locations is 6.94+9.72+6.94+4.63+2.78+1.39 = 32.4%. The closest to this is 37.50%, which grants him a -1½ limitation, and is approximately equal to an Activation of 9-, so the cost would be 18/(1+1½) = 7 active points. With OIF, the real cost would be 18/(1+1½+½) = 6 points.
And finally, he wants to purchase a pair of Heavy Leather Gloves and Boots (2/2 Armor, locations 6 and 17-18). The chance to hit these location is 6.48%. The closest to this is 9.26%, so the limitation is –2½ and the cost is 6/(1+2½) = 2 active points. With OIF it will cost him 6/(1+2½+½) = 2 points. I guess he didn't really gain anything by taking OIF. Tough luck.
So the total active cost of the armor is 14+7+2 = 21 points. The real cost of it is 11+6+2 = 19 points. For all intents and purposes, it acts like any normal power with an active cost of 21, and a real cost of 19.
As an optional rule, depending on the special effects of the power, the GM may allow a character to take the +1 Advantage "Variable Locations". This means that the character can move points from one area of the defense to another, as long as the total real and active costs stay the same. The only restriction to this rule is that no matter how you decide to allocate the points, you must keep the same PD/ED ratio.
Maggen has a personal deflector shield defined as a 10/10 Force Field, Hardened (+¼), Variable Sections (+1), IIF – "Deflector Shield Generator" (-¼), which he usually uses as a 10/10 force field that covers his entire body. The active cost is 20×(1+¼+1) = 45 active points, and the real cost is 45/(1+¼) = 36 points.
While exploring the sewer system of Manhattan (looking for Teenage Mutant Ninja Turtles, no doubt), he hears noises from above him, and wishes to stick his head out the lid and take a look. He shifts all his points to create a force field around his head (locations 3-5). The chance to hit those locations is 4.63%, so the limitation would be –2½. Therefore, he can create a force field as strong as 126 active points (63/63 force field) around his head, since the total active cost will still be the same – 126×(1+¼)/(1+2½) = 45 active points. Even if he knew he would only be endangered by physical attacks, he couldn't have created a 126/0 Force Field, since he must keep the original ratio of 10/10, i.e. 1:1.
One final note - just in case it wasn't clear, these rules work with all forms of personal defense – Armor (sectional armor suits, for example), Force Field (personal deflector shields, e.g.), Damage Resistance (hard sections in monster's hide, e.g.), Damage Reduction (extremely hard sections of monster's hide, e.g.), or anything else you could think of.