Is an opponent flat footed if you are invisible? The rules say that the opponent is denied its dex bonus to AC, but not specifically that this is the same thing as being flat footed.
I have the same situation with feinting in combat.
It has implications for the "Surprise Spell" ability of Arcane Trickster 10.
No. You are flat-footed only at the beginning of combat. After that, you are not flat-footed even if an opponent attacks you while invisible.
I'm still trying to work out whether I think it should be that way -- but them's the rules.
It just irks me that the basic ability to combine sneak attack with spells has such stricter requirements than sneak attack -- it feels like it should trigger when opponents lose their Dex bonus to AC rather than when they're flat-footed. Similarly, it's weird that Shatter Defenses and Catch Off-Guard causes opponents to become flat-footed to your attacks, even mid-combat, when it feels like they should lose their Dex bonus to AC instead.
Oh well. I'll have to be satisfied with 22d6 in a 40' radius in the surprise rouind, then 77d6+98 after that, then.
Surprise round: Freezing Sphere 15d6 + 7d6 Sneak Attack. First Round: Contagious Flame (4 rays) + Quickened Scorching Ray (lesser rod of quicken), 7d6 sneak attack, Sniper Goggles. Second round - extra hits from Contagious flame, Scorching ray + quickened Scorching Ray.
The DM is not giving me sneak attack on the extra attacks from Contagious Flame, even though the rules *clearly* say "as if you were firing them".
But I kinda see his point. 143d6 would just take too long to roll :) Have to settle for 82, assuming all the rays hit.
