how much for limitation affect limited by margin of success

[mehrkat]

OK I'm still working on my Star Wars system inspired by D6. In the D6 world Force is a more random force and the success in the movies is justified by stupid high force powers.

To emulate this for force powers I'm trying to assess the cost of this limitation.

Basically the better your roll the better the effect.

In my opinion. In GURPS this makes mores sense to buy the highest affect and then slap a limitation. To get full affect must get a larger margin of success.

So lets take a force power that increases movement.

Effect:
Description: When this power is successfully activated the character gains a bonus to his Movement. This power can as much as double movement rating.

So (Enhanced Land Move 20/level + Enhanced Water Move 20/level) 40/level -10% force power modifier, Requires skill roll very hard (Control) -10%, requires recharge, 5 seconds -10%, -30%) = making the power 16 points.

So here is where I get stuck. What if it only 1/4 agains movement on a success and adds 1/4 for every 1 success is made by. What is a good cost for that modifier. I'm thinking -30%

any thoughts. Am I not thinking it through somehow?

[the_matrix_walker]

RPK's "Based on Margin" may be of interest to you

Originally Posted by PK

The special limitation, "Damage cannot exceed margin of victory, -50%", is not generically portable without special concern!

Was that clear enough?

The limitation is actually a "behind the scenes" house rule I've had for a while, called "Based on Margin". In essence, say you have to make your roll by X margin to get the full effect. If you succeed with a lesser margin (say, Y), you only get Y/X worth of effect out of it. (Treat margin of 0 as 1.) This is a -5X% limitation.

So let's say that I have Crushing Attack 6d, but I only do full damage if I make my attack roll by 3. If I make it by 0-1, I do 2d damage; by 2, I do 4d damage, and by 3, I do 6d damage. This is a -15% limitation.

So the -50% version is only useable as-is if you have an ability with 10 levels, and your level of effect is equal to your margin of success or victory.

It's a very fair rule, but its complication led me to leave it out of GPP as an official rule. I wasn't even planning on putting it in the Designer's Notes, as it might scare people. :)

This would suggest a -15% limitation for what you want.

[Bruno]

Based on MoS made it into Psionic Powers somewhere, I don't have it at hand.

[Christopher R. Rice]

Originally Posted by Bruno

Based on MoS made it into Psionic Powers somewhere, I don't have it at hand.

Psionic Powers Designers Notes in Pyramid #3/9 Space Opera p. 16

[mehrkat]

Thanks all. I'll check out those resources.

[the_matrix_walker]

You're welcome...

I love this forum! Question asked, One ballpark answer, one in the section, and then right on your base!