Hi,
From the rules, when a creature spends might to use a power, it reduces the penetration.
From my point of view, that means that I never use a power which needs to penetrate with a might cost. Indeed, it's less costly to pay for the improved power required to put cost at 0 than to boost might (or improved recovery), or increase mastery score with intricacy points, or pay for the ability penetration with XP (from base pool or from improved ability).
So I'm really wondering, what's the point to have costs reduce the penetration. I'd understand if the might cost of a power would increase the penetration, because the might pool being limited, it would mean "that power is less useable, but penetrates more". But with a reduction it's like a double punishment: you can't use that power a lot, and the penetration is less than what it should be.
I'm trying to understand what was the underlying reason to have the might cost reduce (and not increase) penetration.
Same reason it works that way for Magi. The higher the level of the spell, the less penetration you get for that casting total. For a creature with a might score, the higher the cost of the power, the lower the penetration. In other words, in both cases, less powerful abilities are more likely to work against protected targets.
Jason is right in my view. If you build powers by the book, the higher level they are, the more they cost. So that means your monster with the one-shot kill power is unlikely to be able to use it on an experienced magi, but might still have a shot at using a small power on him, while being able to one-shot the grog. Of course... you can use your points to reduce the cost of everything to zero. But it's not how creatures are intended to be designed, in philosophy. Of course, if you decide to play a more lethal variant of ars, there's nothing fundamentally wrong with it. There's enough flex in the system to allow it.
To agree with the other respondents, it's because Ars is a healing-rare system. Making monsters easier to kill after they've killed your grogs is a design choice, I presume
For magi, it works very well because they generate a casting total and you can then say "the magical energy is fixed, but if the spell is less, then the penetration is more".
Monsters do not really do that casting thing. And the rules allow them to use 0 cost powers which makes this argument not really valid.
You say that the philosophy of monsters is not having the cost set to 0. Were is that said? obviously any PC would do so because it makes it playable. (I have seen 3 players design magical creatures or using magical powers, none of them had a power with a cost being not 0, because either it spend fatigue which you need, either it lowered the penetration and made them useless against low might enemies.
So why would NPC do differently? I'm not really fond of the fact that NPC should be weak for the pc to kill.
I'm not really wanting a more lethal version, it's just that I'd found it more fun that a creature could have the decision to make:
if I use that power, I have more chance to hit that person behind the shield man, but I can only use it twice;
or I use this power which i can do at will, but i'm not sure it's useful.
In the current rules I feel like creatures with "costing" and "0 cost" powers have this choice:
I can use this power some times and it will never hit
or I can use that power at will and it may hit.
and it doesn't seem a fun choice, if it is even a choice.
While I cannot speak to the mind of the designers, I'm pretty sure it's because the aforementioned link to Hermetic Magic rules.
It makes sense that Magi lose penetration when more of their spellcasting power goes into 'bigger fireball'. Because everything in the game uses Hermetic Magic as a baseline, it means that bigger, better spells always have less penetration... and the baseline for Might Powers is that more powerful abilities cost more might, thus have less penetration. Just like magi. The amount of might spent is a direct correlation to how hard it is to cast, rather than how powerful it is. The harder you have to try to make it go, the less energy in the penetration.
If you wanted a saga where the more Might something takes, the more power it hits with, that's a reasonable change, but not the default...
Yes of course, I'm not really looking to change that in our saga (it would be fun, but it would require too much work to adapt every creature template).
It's just a discussion I started because I wanted to find if I'm the only one finding the choice of creatures using powers not really interesting (see previous post for an explanation of what I mean).
If I wanted that change... I'd probably add the vis rules equivalency.. Default penetration is its Might score, and it gets +2 penetration per Might spent.
It's not exactly what I was saying, no. Setting a power's cost to 0 is fine. But it's the exception, not the rule. Feel free to do it differently in your game. Do I consider penetration when designing a magic character? Sure. I don't always set everything to zero for sure, however.
That's core. RoP:M p.29 : "Magic characters can consume vis, activating it in the same way that magi do. Each pawn of vis from the same Form as the character’s
Might Score will immediately replenish 5 Might Points, or 2 Might Points if this vis is associated with any other Art; and when consumed, a pawn of vis will give the character a +2 bonus to its Penetration when activating powers appropriate to that type of vis."
I don't recall if it's explicitly stated for creatures of Might from other realms.
Sorry that was unclear - what I meant was that if I wanted Might spent to increase power (rather than decrease it as core), I would not have the might cost reduce a power's penetration by 5, and instead increase it by 2.
I have found a lot of the rules like this make sense when explaining how things work, but sometimes can create weird situations when you're designing things using the numbers. Most players I've seen designing their own familiar will reduce all powers that require penetration to 1 or 0 might spent for penetration and ease of spending.