PLAYER: Can I melt the ice golem by throwing cold spells at it?
GM: No
PLAYER: Can I kill the Acid Elemental by throwing acid at it?
GM: No
Are we talking about D&D? There were ways to pierce elemental immunity there.
PLAYER: Can I open my manacles with my lockpicking skills even though they have been magically welded instead of having a lock?
GM: No
If your lockpicking has a supernatural nature to it? Sure, why not?
PLAYER: Can I socially fast-talk the gelatinous cube into letting me pass even though it's mindless, blind and deaf?
GM: No
Then grant it a mind, learn a telepathy power, succeed on an <social skill of your choice> check, there you go.
PLAYER: Can I bribe the traps in the dungeon into not closing if I step on them?
GM: No
I guess that depends on whether animism exists in the setting or whether you can talk to objects otherwise, now doesn't it? However, in this case you're applying a social context to a physical challenge. This is not the case with Physical Immunity, where a physical challenge cannot be overcome with a physical attack. Otherwise, refer to the above.
The prevailing opinion on Physical Immunity seems to be that it is entirely based upon GM fiat. If that is the case, then it should not be given a refresh cost.
Yeah, I think that nails it.
I mean, if Physical Immunity is already meant to be a plot device power, then why is it given a Refresh cost at all? I mean, it's not entirely inaccesible. Note that PI is an option for Changeling/Scion type characters which means it should be at least balanced for PC use.
Anyhow, the power just seems excessive and it entirely strains my suspension of disbelief. I mean, even characters in freaking /Nobilis/, who can casually put out stars and juggle continents can't get this level of invulnerability(at least in 3rd edition, it was possible in 2nd).
I probably wouldn't mind this so much, as someone mentioned, if it was explictly noted that plot-level events can pierce even PI.
If you need a character that's nigh-invulnerable, then an easier thing to do would be noting that Toughness could be expanded indefinitely(ie. -8 for Armor 4, 8 boxes, -10 for Armor 5, 10 boxes etc), expanding regeneration into new areas and leaving PI to cover only specific threats(like the Outsider immunity to magic or being immaterial, I don't mind those so much).