Sigh. Making me quote the whole thing, aren't you?
See the underlined part? See the comma? See the lack of a period?
Indeed- you might recall I pointed it out to you.
"you gain a bonus"
Everything after that is a Bonus.
Which phrase is followed by "as well as extra damage"
If I write a sentence: "you gain a bonus apple, as well as an orange", it does not follow that the orange is now an apple.
Sorry, but I spent years reading contracts and screwing people over with them and getting paid for it.
Good for you! I still am: TX Bar number 00796145, mostly in Entertainment law. Got an MBA as well, certified as a mediator and working on my arbitrator certification as well. So you could say I know a little something about contracts.
That makes the damage bonus damage. Not Extra damage. Extra damage stacks, bonus damage does not.
Except for the fact that the subsequent phrase in question
explicitly and unequivocally uses the terminology "extra damage". See your own quoting of the rule- that term is at variance with the main clause. Had they NOT used the specific term "extra damage", I probably wouldn't be writing this post.
Simple fact is, the 3.X's designers were not (AFAIK) attorneys, and often got sloppy with their use of language, which is one reason I really don't put much faith in RAW interpretations where the language is in conflict.
I've written 112 handbooks on 3.5.
I freely admit that I am not a game designer.
Trust me. I know how to read the rules.
My first semester of law school, I got a perfect illustration of the impact of language upon rules. A man who help redraft the Tx criminal code in the late 1980s-early 1990s was talking about a specific section of the code. A student who was not a native English speaker asked about that section and how it was read- her interpretation of a key- but not defined- term was very different.
He looked at it. We had 10 minutes of silence as that man stood in front of the class and studied the rule and the dueling understandings of the key term. He then noted that her reading was- linguistically speaking- as valid a reading as the way his group had intended. He thanked her, and told the class that he was making calls that day to get that code redrafted, because otherwise, a clever attorney would be able to sent the system chasing its own tail for quite a while using her reading.
The point? Knowing how to read rules is great, but sloppy drafting can derail a rule. Here, we have the superior clause saying one thing, but the subsequent clause explicitly telling us something else entirely.
Burn as many spells as you wish, they will not stack.
I have played it both ways. It really doesn't make a huge difference in the long run. Play as you like.