Armor Blocks are a special kind of block (for exotic martial artists, usually) where, when you perform a Block (spend REA) you wind up with extra armor if your block fails (if it succeeds the attack misses and so you do not need armor). There are several of these (negative Damage Modifier Blocks, ADP Blocks, and maybe some others) that all work the same way: you pay the REA, you try to block the attack. If it fails, you get the armor.
The good news, for exotic martial artists, is that if you just have the basic version it's pretty cheap: firstly it doesn't even apply against half the attacks (you don't try to block bullets) and secondly, each block costs 3 REA so if you do more than one you lose an attack.
However, the bad news (for the game system designer) is that we'll rarely see one of these "in the wild." What we'll see instead are blocks where you can block bullets and other ranged attacks (due to a separate special cost) and we'll see characters with Quick Blocks (1 REA Block/Dodge actions) gravitate towards something like this since it's pure gravy if you have a 1 REA Block you can use against anything--at it's worst, it's paying 1 REA for extra armor!
This raises some concerns ...
The first concern is that if you have the "basic version" of the Block (not vs. Ranged--even the armor won't work) and costing 3 REA (out of an average of 12 REA) then it turns out that even if the armor you get is like 100pts of armor the real value of the block is fairly limited. It'll really shut down a 1-on-1 HTH fight--but it won't do anything against ranged and if you're fighting 2 on 1 or more your REA will go fast. So the "basic form" of the power gives a lot of armor for not-too-many points.
The second concern is that of "stacking." In JAGS, as much as is possible, we want you to be able to mix and match things for good effects. So if you have some ability that gives you 1-REA Blocks (which is pretty cheap) and you have another that gives Armor Blocks (kinda cheap) then if you have both we want you to be able to throw Armor Blocks for 1 REA (at least once or twice a Round). That dynamic makes character creation fun. But how do we cost for it? That, I think, is a philosophical question.
The Philosophical Question
The question is: do we cost it assuming the character will max out their effectiveness? Do we cost it based on the character having median effectiveness (i.e. works vs. Range but not for 1 REA?). Do we cost it based on the character not doing anything fancy?
The way to look at it is: what's the damage in each case?
- Cost Based On Max: in the 16 AP herd fight the maximal effective form (2 blocks for 1 REA with 8x Level Armor if the block fails, the block works vs. Range) gives you a super-high 94% POV. This is something like 14 AP out of 16. If we costed based on that a character without all those benefits would wind up broke if they purchased an armor block compared to ...
- Cost Based On Nothing Special: The cost for just the straight 8 AP Armor Block at 16 AP is around 2 AP. That's a massive difference. If we just went with the straight cost? Then either all those extras cost around 10 AP (which they do not--each one taken separately gives you around another 1 or 2 APs worth of cost) or else we really reward characters who sexy-up their Armor Blocks.
- Cost Based On Median: What I could do is split the difference and cost it around 7 AP (about right in the middle). This would reward sexy Armor Blockers to the tune of about 7 AP and would screw basic Armor Blockers to the tune of about 6 AP. While it seems like a good solution it might actually be the worst.
What Else Can We Do?
Well, the obvious answer is this: an Armor Block can never be 1 REA unless you buy it special that way. If you get some 1 REA Blocks because of [whatever] that's all well and good--but they will not work with your Armor Block.
The good news is that we can cost these things separately and we can sell the "combos" with a fair amount of ease. It removes some of the possibilities from the game--but it prevents degenerate designs. What have we learned from this?
What Have We Learned?
The key thing we've learned, I think, is that we need to think carefully about how much work we want/expect the Player to put into character design. One of the most demoralizing things I've seen video games do is create the opposition so that you need optimal builds to compete. This sucks for me because (a) I will never play enough to figure out the maximal strategies (b) the maximal strategies may not be fun for me anyway and (c) I hate having to go online and "do homework" to figure out how to play a game.
So I don't want to do that.
On the other hand, we can't ignore that some builds are going to be better than others and that will effect play. I think that having character-design be interesting and more than skin-deep is cool but I don't want to force it on people. So what can we do about that?
The ultimate thing to do from a balance perspective would be to have character cost be empirically determined you'd build your character using a computer tool (a web-site or desktop app) and it would run that character build "against the herds" and would tell you the cost. You'd change things and it would re-adjust. This would give you a "real cost" (assuming the herds were picked by the GM to be relevant to the specific campaign) and unless you could do some very complex math in your head, character creation would be trial-and-error ("Oh, I added an armor block and shot up 50 AP ... hmmm.").
The next best thing to do is to simply put in rules where necessary to prevent degenerate situations but try to keep the points as fungible as possible. If we do things right, 5 AP in "Armor Block" should, most of the time, really be as good as 5 AP in Armor or ADP or Force Field or whatever. It should be as good as having 5 more AP in an attack (but 5 fewer in defenses). That's the goal.
We're never going to get there, of course--this is too complex (and we're not even balancing against normal character builds--although we've done a good deal of testing)--but it is the goal.
We're marching towards it.