Looking for advice on how to create a costs x energy limitation.

[Jaware]

I'm trying to build a limitation for an ability sort of like "costs FP" and "Costs HP" but what I want it to do is cost a percentage of the available pool of energy.

Like for instance a "costs 20% of your FP"

I am running into trouble though. I thought about making it a "either or" one but that makes it effectively costs a 0% modifier.

I am no gurps wizard or anything, but I would think that it should be worth a bit more than a mere 0%.

Mostly because if you are at 2 health, "20%" is effectively half your health.

Even something like cost 50% of your FP, if you are at say 4 FP, out of a possible 15, than that's quite debilitating limitation.

It just seems to me that this would be a very hefty limitation.

Ideas anyone?

[Jerander]

Originally Posted by Jaware

I'm trying to build a limitation for an ability sort of like "costs FP" and "Costs HP" but what I want it to do is cost a percentage of the available pool of energy.

Like for instance a "costs 20% of your FP"

I am running into trouble though. I thought about making it a "either or" one but that makes it effectively costs a 0% modifier.

I am no gurps wizard or anything, but I would think that it should be worth a bit more than a mere 0%.

Mostly because if you are at 2 health, "20%" is effectively half your health.

Even something like cost 50% of your FP, if you are at say 4 FP, out of a possible 15, than that's quite debilitating limitation.

It just seems to me that this would be a very hefty limitation.

Ideas anyone?

This could be a variant of the Variable modifier for Costs FP (I believe it's in Powers)...

One question, does the effect scale with the pwoer put into it?

Second question, does it always round up to 1-FP (or HP)? What happens when the % falls below one? For instance, an ability costs 20% of your FP and you only have 3-FP left? Does it round up to 1-FP, or does the ability become unavailable?

[Varyon]

This is something that's extremely complicated. Basically, you're starting off with a "Costs n FP" Limitation, where n is 50% of your maximum. Then, you've got something of an offsetting Enhancement where that FP costs decreases the lower your FP is, and a further Limitation where you (presumably) cannot use the ability if your FP reaches 0.

The first part is easy enough. The third is going to be a sort of Accessibility Limitation, and I'd eyeball it at around -10% or so. The second is the nasty one. Offhand, I'd say it makes the Costs FP Limitation be worth between 50% and 75% of normal. So, for a character with 15 FP, the "Costs 20% FP" Limitation is going to be -10% (unusable at 0 FP) + -15%*.75 (Costs 3 FP, x0.75 for being variable), for a total of -21.25%, which we'd probably round to an even -20%.

[Jerander]

If the power of the ability scales with the amount of FP put into it, then it becomes pretty easy. Variable Costs FP with a limitation (Uncontrollable?) that dictates how much FP you put into it.

[Jaware]

Originally Posted by Jerander

If the power of the ability scales with the amount of FP put into it, then it becomes pretty easy. Variable Costs FP with a limitation (Uncontrollable?) that dictates how much FP you put into it.

No. It's the same ability. It just costs different based on the available resources.

What I'm planning on making is my take on a bloodmage. Where the powerful abilities cost a different amount based on the available HP.

[Jaware]

Originally Posted by Varyon

This is something that's extremely complicated. Basically, you're starting off with a "Costs n FP" Limitation, where n is 50% of your maximum. Then, you've got something of an offsetting Enhancement where that FP costs decreases the lower your FP is, and a further Limitation where you (presumably) cannot use the ability if your FP reaches 0.

The first part is easy enough. The third is going to be a sort of Accessibility Limitation, and I'd eyeball it at around -10% or so. The second is the nasty one. Offhand, I'd say it makes the Costs FP Limitation be worth between 50% and 75% of normal. So, for a character with 15 FP, the "Costs 20% FP" Limitation is going to be -10% (unusable at 0 FP) + -15%*.75 (Costs 3 FP, x0.75 for being variable), for a total of -21.25%, which we'd probably round to an even -20%.

I like this, but if I could, I'd like to have it just a drag and drop modifier, with the same math and what not, but regardless of the am out available to the character.

So for instance, they have a pool Energy Reserve of 10, 20, 30, or any number in between it would have the same limitation value. Where my players and I wouldn't have to adjust the cost every time their maximum has

[Jaware]

Originally Posted by Jerander

This could be a variant of the Variable modifier for Costs FP (I believe it's in Powers)...

One question, does the effect scale with the pwoer put into it?

Second question, does it always round up to 1-FP (or HP)? What happens when the % falls below one? For instance, an ability costs 20% of your FP and you only have 3-FP left? Does it round up to 1-FP, or does the ability become unavailable?

It will always cost a minimum of 1. So you can use it if you are at 1 FP or 1 HP. Albeit with cosequences

What do you mean scale? Like the old fireball spell, the 1, 2, or 3 FP per second up to your Margery level?

I wasn't thinking of it, but it would probably be something to look into

[Anaraxes]

Originally Posted by Jaware

Where my players and I wouldn't have to adjust the cost every time their maximum has

So, you want a limitation that's the same amount, X FP, every time you use the ability -- but that between different characters, X is a different number because they have different starting FP?

Just use Costs FP, and buy it at different levels on different characters. Disallow builds that don't have Costs FP in the proper portion to FP (or HP).

Most of the comments are talking about a Limitation where the amount of FP needed changes each time the same character uses the ability, as your FP drops. 50% of 10 FP is 5; then you have 5 FP, so 50% of 5 means the next use costs 3; the third use you start with 2 FP, so it costs 1 FP.

Varyon has a theoretically right approach there, but if you don't feel like summing an infinite series, you could just use Limited Use, picking the number number of uses you'd actually get. (In the above example, 4.) You could add Takes Recharge to represent the rest time afterward to regain the FP. You'll get the same net effect: use the ability N times, and then have to wait.

[Varyon]

Originally Posted by Jaware

I like this, but if I could, I'd like to have it just a drag and drop modifier, with the same math and what not, but regardless of the am out available to the character.

GURPS... doesn't really work like that. You could assume that the current prices are appropriate to a character with HP and FP 10, in which case it's -10% for not being able to go below 0 and then each 10% FP is -3.75%, each 10% HP is -7.5%, but then most characters are getting less points back than they arguably should.

[Jaware]

Originally Posted by Anaraxes

So, you want a limitation that's the same amount, X FP, every time you use the ability -- but that between different characters, X is a different number because they have different starting FP?

No. You must have misunderstood me. I want it to be a set amount for character creation. Not for casting. For casting I want it to cost different amounts depending of the available amount of energy available.

Originally Posted by Anaraxes

Most of the comments are talking about a Limitation where the amount of FP needed changes each time the same character uses the ability, as your FP drops. 50% of 10 FP is 5; then you have 5 FP, so 50% of 5 means the next use costs 3; the third use you start with 2 FP, so it costs 1 FP.

This is correct. I want it to work like this. With a minimum cost of 1.