What happens if you are caught illegally downloading, say, "Baby" by Justin Bieber? (Assuming the justice system decides to make an example out of you, of course.)
Hopefully, they'll shoot me for my incurable lack of taste.
On-topic (ish) though, Arcane Thesis is not a well-worded feat because it allows for at least four interpretations:
- because it says
a metamagic feat, you can only apply it if you use one such feat. Hence, no invisible empowered magic missiles.
- you can apply multiple metamagic feats. Calculate the total level, then subtract 1. So, an invisible empowered magic missile is level 2 (1 + 2 + 0) -1.
- you can apply multiple metamagic feats. Calculate the adjustments one at a time; at no step should the total level reduce. So, you start with magic missile (1), add empowered (1 + (2-1) = 2), add invisible (2 + (0) = 2), to get an invisible empowered magic missile at level 2.
- you can apply multiple metamagic feats. Calculate the total adjustment, subtract the number of feats applied, and add that to the base level. The total cannot be less than the base level of the spell. Hence, an invisble empowered magic missile would be level 1 (1 + 2 + 0 - 2feats = 1)
The strict wording of PHBII says the first of these, although I'll grant you that that's very much a nitpick. I actually think the second is the best interpretation. The third, however, is the one that the designer indicates was his intention, and also seems to be the one that WotC's customer service agrees with (though their answer doesn't rule out 4, I'll grant you).
The fourth option I'm afraid I just can't agree with. Firstly simply because it's broken. Secondly because it gives an absurd result - an invisible empowered spell is now lower level than just an empowered spell. And thirdly because spellcasters are already overpowered in the game in general, so I'm very much disinclined to interpret everything possible to give them yet more power.
Beyond that, I think this may be a case where we have to agree to disagree.
Having an Empowered Magic Missile at a level 1 slot is quite something, don't you think?
Well, yes, but by your interpretation of Arcane Thesis, you don't need Stripped Spell for that - your example said that an invisible empowered magic missile would be level 1 already.
And my nitpicky read of Arcane Thesis doesn't allow it, due to the "a metamagic feat" issue - Empowered and Invisible, or Empowered and Stripped, would each be two such feats.
Funnily enough, in this case it is the commonly-accepted interpretation that allows Stripped Spell to cause a problem (where you have 1 + (2-1) + (-1) = 1).
However, having said all of that...
I think most people on this thread are pretty much in agreement that Stripped Spell is problematic enough on its own, without worrying over-much about the interactions with Arcane Thesis.