From looking at the numbers on those powers Id be amazed if I missed them, the default slot would be fine unless I was plying special IOs into them.
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
The passives give a base 5.625% resistance, which when 3-slotted becomes 8.72%. They would be pretty low priority powers for me to get, I'd rather get Tough and/or Aid Self instead - both will significantly boost your survivability.
I'd definitely get Tough and before I9 I'd skip the two passives, but now I'd definitely take them and slot it with uniques, such as Karma +3% defense or Impervium Armour and/or Impervious skin mez resistances and psionic dmg resistance, but IMO, Tough is a must for Inv scrappers.
Personally I never been fond of Aid self unless you want to PvP.
Invulnerability doesn't shine on defence, it shines on lethal/smashing dmg resistance, but it lacks on other types of dmg, specially psionic so careful with the clockwork king 
[ QUOTE ]
Hello,
I've been playing an /Invulnerability Scrapper and, well, he's very good at wading in. He's Claws/Invulnerability so he may not be the biggest damage dealer but he can survive a good while (including solo) and has a few ranged attacks which I've found mighty useful in teams.
However, will I need the 'extra' powers (Resist Energies and Resist Elements) as I heard someplace that Invulnerability really shines in the defence department.
If the answer is yes then is it worth three-slotting those powers?
Also, whilst you're there (by you I mean anyone who can be bothered to reply), are there any snippets of advice on slotting and using the Inventions system to increase survivability?
[/ QUOTE ]
First of all, /invuln scrappers ftw! I've been playing mine since I3 and it's coming even better as the issues come.
I only currently have the resist energies passive slotted with the Steadfast Protection: +3% Defence unique IO. Mostly got it for the +3% psi def though. If you have the space in your build to get both those passives (before anything else more important like travel, stamina etc) and slots to put in them I think it's worth to slot them with 3 impervium armors in each (+3% psi res, res and a res/rechg) to get 6% psi res and 4.5% psi def total.
Neither of those two is needed though. I picked resist elements at lvl 49 in my build.
For IOs that increase survivability I'd say your best bet is +rechg (to get dull pain up more often and eventually get it perma), +psi res/def (to fill in the hole of invuln) and after that +regen and +recov (to keep toggles running and HP regenning).
[ QUOTE ]
I'd definitely get Tough and before I9 I'd skip the two passives, but now I'd definitely take them and slot it with uniques, such as Karma +3% defense or Impervium Armour and/or Impervious skin mez resistances and psionic dmg resistance, but IMO, Tough is a must for Inv scrappers.
Personally I never been fond of Aid self unless you want to PvP.
Invulnerability doesn't shine on defence, it shines on lethal/smashing dmg resistance, but it lacks on other types of dmg, specially psionic so careful with the clockwork king
[/ QUOTE ]
The defence of invuln is actually great. With my build I'm getting 30% def versus all but psi (against which I have 20% def at all times) when there's 10 or more enemies around me. That's quite a lot I'd say.
Tough isnt something I'd consider a must for an invuln scrapper. I dont have it and I prefer aid self anyway (and that's what I have atm).
- @DSorrow - alts on Union and Freedom mostly -
Currently playing as Castigation on Freedom
My Katana/Inv Guide
Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either. -Einstein
[ QUOTE ]
The defence of invuln is actually great. With my build I'm getting 30% def versus all but psi (against which I have 20% def at all times) when there's 10 or more enemies around me. That's quite a lot I'd say.
Tough isnt something I'd consider a must for an invuln scrapper. I dont have it and I prefer aid self anyway (and that's what I have atm).
[/ QUOTE ]
What I meant is that defense is not the main feature of Inv, on mine it's good bacuse of sets and build designed towards that (plus Divine Avalanche). The main feature of an /Inv toon is the high lethal/smashing dmgres.
The possibilities of the /inv scrapper after I9 are interesting though, 30% defense is what an SR could get before I9 with all the SR toggles 3 slotted for defense plus CJ with 1 defense enhc on base slot (as per old Hero Builder).
True, the high smash/lethal resistance really helps pre-20 where most of the damage is S/L.
The DEF part there is just awesome for powers like aid self, I think.
And when I just think of the pre-I9 SR defence levels combined with invuln resistances it just gets me drooling to find those 10 enemies 
- @DSorrow - alts on Union and Freedom mostly -
Currently playing as Castigation on Freedom
My Katana/Inv Guide
Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either. -Einstein
I have neither Aid Self or Tough and I manage just fine.
IMO Invuln is about Defence, not resistance. Your main survivability comes from your stacked Defence, not your smashing/lethal res. you NEED to get the bad guys around you. Ranged can just kill you so quickly. FWIW I don't have either passive, But am considering taking them and 3 slotting with IO's or Recipe sets. Might consider Aid Self, possibly.
Defiant 50's
Many and varied!
@Miss Chief
Hello,
I've been playing an /Invulnerability Scrapper and, well, he's very good at wading in. He's Claws/Invulnerability so he may not be the biggest damage dealer but he can survive a good while (including solo) and has a few ranged attacks which I've found mighty useful in teams.
However, will I need the 'extra' powers (Resist Energies and Resist Elements) as I heard someplace that Invulnerability really shines in the defence department.
If the answer is yes then is it worth three-slotting those powers?
Also, whilst you're there (by you I mean anyone who can be bothered to reply), are there any snippets of advice on slotting and using the Inventions system to increase survivability?