[PU4, Powers] What does Cosmic power modifier actually do?

[David Johnston2]

Originally Posted by Gurps Fan

Yes, Powers says that the first +50% portion of any Cosmic modifier is counts as a power modifier, but that's strange. That means that if I buy any of instances of Cosmic listed on pp. 6-9 in PU4 for any of my ability, it automatically becomes one that "originates from primordial energy of cosmic somesuch" because it's now part of Cosmic power.

No it isn't. Either you have the cosmic power source or you don't. Having the cosmic power source means that every single advantage you have has some kind of cosmic modifier, but not vice versa.

[Gurps Fan]

Originally Posted by David Johnston2

No it isn't. Either you have the cosmic power source or you don't. Having the cosmic power source means that every single advantage you have has some kind of cosmic modifier, but not vice versa.

I see. Confirmed in the description:

Originally Posted by Powers, p. 21

This power modifier counts as the first +50% of all Cosmic enhancements added to the power’s individual abilities. For instance, if the ability includes an irresistible attack, it costs +250% over and above the +50% in the power modifier, for a total of +300%.

I.e., If your IA is an ability that belongs to Cosmic power (= modified with Cosmic power modifier, +50%), making it an irresistible attack costs extra +250%. If your advantage is "raw", not part of any power, making it irresistible costs extra +300%. In effect, if the advantage includes any one of instances of Cosmic enhancement listed on PU4, pp. 6-9, the character can choose to declare "this advantage is part of Cosmic power" for free.