"1/2 as effective against X" Limitation and Player Controlled Allies
 

Is there a RAW legal way of having a limitation for making an ability that is only half as effective against a certain category of targets? What about 1/4, or even an enhancement that makes it x2 or x4 more effective? I'm thinking primarily in terms of using it to modify Injury inflicted, and I know I could give all the targets the appropriate advantages and disadvantages to simulate this, but assume this is not desirable.

If all Player Characters have certain kinds of Allies which are Player controlled but not Player Character controlled, should this simply not be paid for in Character Points but be a campaign switch?

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

In the limit you can always buy the ability twice, once with Not on X and at a different level with Only on X. Mind you there are a lot of combinations that will give you less ability against either than you would have buying it with no limits for fewer points, but it will give you *a* price for any combination of multipliers.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

While that's a good idea, it's not particularly efficient for what I have in mind. I'm thinking of characters within X category and all of their abilities have varying effectiveness against characters of A, B, and C categories. Think Elemental Rock-Paper-Scissors. What I'm saying is I think it'd be a lot less hassle if a category could be expressed as a modifier. E.g., rather then buying two abilities with "Not on Atheists" and "Only on Undead", but just one ability with "Holy".

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

You can certainly make up a single name for a category and give it a value so that you can reuse it. malloyd outlined the procedure to estimating the value the new Limitation ought to have. An ability that does half damage half of the time would have full price for half of the levels, and a (say) -20% Accessibility limitation on half of the levels, which works out to -10% for the full price of all the levels. Once you're happy with the value, just name it and apply it to other abilities. You don't have to actually work the procedure for each individual ability.

Note that combining several categories into one Accessibility isn't done by adding the separate limitations, because the Accessibility scale isn't linear. You'd add the probabilities of being useful first, then check that result on the Accessibility scale.

An ability that does double damage versus a category is the same thing as an ability with twice the damage, but with half of the levels limited as "Only Versus Category". Just switch your point of view around from "double damage versus category" to "half damage versus not category".

As for the second question, it's common enough to games to have campaign advantages that are simply assigned to all players without paying for them. You can either ignore the cost, or just bump the campaign starting total to have extra points to cover the required campaign advantages, to suit your taste. CP totals are a relative measure, so either way works.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

Ah, alright. Mind you, math is my kryptonite, so I think I understand this:

So lets say there's 18 categories. Category X is twice as effective against 3 out of 18 of those categories, but is only half as effective against 7 out of 18 of those categories. This works out to being overall useful roughly 20% of the time, so Category X would be a -30% modifier. Did I get that right?

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

What I would do is put limitations on the differences. For example, if it was a 6d Crushing Attack, that's

3d Crushing [15] + 3d More Crushing (11/18 categories only -15%) [14.25] + 6d More Crushing (3/18 categories only -35%) [19.5] for a total cost of [48.75], which rounds up to [49]

EDIT: Note that these modifier percentages are based on the notes for Accessability in Powers.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

The simplest way to do this would be for all Water types to have Injury Tolerance: Damage Reduction 1/2: Limited Defense (Fire) [30] and Vulnerability (Lightning): Injury x2 [-30].

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

I was almost about to ask if I could just have a straight up equation to plug the appropriate numbers into the right places because word problems are evil, and viola, here's one! Now, what if certain categories are immune to that category?

You know, I actually thought of this. Whip up Meta Traits for each of the categories and then give all the abilities the appropriate -0% category modifier to note how it interacts. The thing is though is that characters could be a combination of any two categories and that would mean making up a lot of those Meta Traits.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

If you're a Rock/Water type, your IT:DR and Vulnerability cancel out to taking normal injury, and combining types does not increase the values of either IT:DR or Vulnerability.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

Yes, and if both categories are weak to a category that increases Vulnerability, or if both resist a category and that increases IT:DR, etc.. But I really want to avoid all that. The simplicity of just slapping on a single modifier to model the interactions between the various categories rather then Meta Traits... because, say, if we have 18 categories that's potentially 171(!) Meta Traits to be statted out. Instead, while characters might be of two different categories, their abilities may only have mono category modifiers, e.g. the Rock/Water combo character's abilities might either have the Rock or Water modifier. This way I'm just working with 18 different modifiers. It saves my sanity. x_x

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

No, I just said that they don't add to each other. Thus, you just determine what hurts what and what doesn't hurt what, and simply drop things that counter each other if a character mixes types.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

Yeah, I get it. If Rock is weak to Water, and Water resists Water, then Rock/Water takes neutral injury from attacks of Water. What I'm saying though is if both categories have a common weakness, then instead of Vulnerability x2, it's x4. If they both have a common resistance, then instead of IT:DR 1/2, it's 1/4. I hope we're on the same page now.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

From the discussion of damage types and Allies this sounds like GURPS Pokemon

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

"!"

I intentionally omitted the subject matter hoping it would therefore attract more replies and thus not deter others from commenting due to either not knowing much about Pokemon or simply disliking it. My ruse would seem to be up though. ^_^

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

Does it work that way in Pokemon now? Either way, increasing resistance/weakness is still just "you have both of these categories applied to you." No extra work is required to allow somebody to mix two types.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

My concern with elemental rock-paper-scissors is that it tends to work best with games that have piles of hit points: If you have 100 HP and I deal 10 damage, then it will take me 10 turns to defeat you, unless I use an attack that you're weak against, in which case it'll take me 5 turns. There's a sort of calculus that you can balance your critters around.

But GURPS doesn't work like that. If I have 10 HP, and you deal 10 damage, then it doesn't really matter to me if I'm vulnerable to it or not, I'm going to try to not get hit either way, so either way, I try not to get hit.

If I had a DR against certain attacks, then suddenly that changes: If I am strong against your attack, I might not bother to defend and I might just AoA instead. Or, what if all the characters in your game had "Higher Purpose (Elemental Affinity)" that gave them a bonus against certain characters. In fact, if this all balances out, why not make it a feature? If Earth characters get +1 vs Water characters and a -1 vs Wood characters, then it's pretty much a wash, and they just have that affinity, and you don't worry about the cost. In any case, by making it a flat modifier, then it impacts my ability to fight, not just my ability to inflict damage.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

For Pokemon, at least in the video game canon, it isn't uncommon for the critters to get K.O.'d in 2-4 hits, so the low HP norm of GURPS might just be fine as is. The art of making them last longer in a fight is paying attention to Typing, e.g. If my Pokemon gets K.O.'d I might want to send out a Pokemon who has the strongest resistance to the opposing Pokemon's Type, or attempt to counter with a stronger offensive Type instead.

Unfortunately, not all Types are equal. For example the Bug Type has weaknesses to the 3 most offensively powerful Types, is resisted by 7 other types, has so-so resistances, and is only advantageous against 3 Types which usually have a means of countering the Bug Type anyways. Besides how their Type effectiveness, they're generally an overall weak bunch... then there's the Dragon Type. We won't talk about the Dragons.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

An idea that came to me just now that would make these modifiers more appropriate is if they were also Power Modifiers. Pokemon within their given Types generally have common powers in that they share, aka "Moves/Abilities" that they learn or innately have. I think with the method previously mentioned for figuring the modifiers would work just fine for this.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

... *facepalm* I think I'm now just understanding this. So basically, if I have a Pokemon with Water Type Meta Trait, and then also a Rock Type Meta Trait, they just mesh accordingly. Am I understanding now?

This is actually a lot simpler, you're right. So I can just hash together the 18 Meta Traits... and -0% Type modifiers on abilities so they interact with the Meta Traits.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

Yep. Just put both meta traits on the sheet, and cross out things that cancel each other.

Re: "1/2 as effective against X" Limitation and Player Controlled Allies
 

The other advantage of using Meta-Traits instead of modifiers on attacks is that you can then consider non-IA damage sources to be typed. Thus, if your grass pokemon gets burnt in a mundane bonfire, you can consider it weak to it without worrying about whether you're jipping it. Note that you don't neccesarily have to do this. It's up to you as GM whether non-pokemon damage counts as typed, but this system allows it.