Thanks
As the Umpire said, "I call 'em as I see 'em, no matter how unpopular that may make me!"
And slaying arrows can be hit point damage, it just seemed to be presented as "dragon failed his Fort save and died." And, if the slaying arrow deals "1,000,000 damage to the creature that fails it's Fort save" then I'd also say that it's effectively bypasses the hit point mechanic. If it just magnifies damage or otherwise increases it, then it's well within the limits of hit point mechanics.
Though, since we're talking about D&D, I don't believe that this version of slaying arrows have been historically used. Though I am fuzzy on this, so I could very well be wrong.
Well, it all depends upon the parameters of the discussion, I suppose. I was defending the hit point mechanic, which includes not only how it is used in Official D&D Products.
It should be pretty easy to image an arrow that does +1d8, +2d8, +4d8, etc., damage.
In my own game, I included a mechanic that specifically allows characters to do this under some circumstances. The more skilled a character is, the more extra dice of damage he can potentially do. This makes ambushes a bit more deadly, and it makes even high-level characters think twice when surrounded by dozens of armed crossbowmen.
EDIT: As a heroic (6th level) bowman, Bard would presumably have 7 ranks of archery. Getting the drop automatically grants one extra die of damage, and he can spend ranks to gain 3 more; so +4d8 damage. This is in addition to the base 1d8 for the arrow, whatever bonus Bard gets for pull strength, and whatever bonus the Black Arrow gives him. If he manages to roll a critical hit, that's another 1d8. So, Bard does up to 6d8, with (say) a +2 bonus to damage for his pull strength, and a +2d8 for being a Bane weapon against the dragon. He strikes with +1 for remaining archery ranks, +4 for getting the drop, +1 for Dexterity, or +6 total. Assuming that the Black Arrow grants him nothing.
Bard then does a potential 8d8+2 with that arrow, ranging from 10 to 66 points of damage. All within the confines of a hit point based system!
Now, let us imagine that Smaug is not instantly slain, but the damage is sufficient (greater than 1/3 hp) to make him unable to fly. He now comes crashing down from 100 feet up onto Laketown. In RCFG terms, the 1st 10 ft. does 1d6, the second does 2d6, the 3rd does 3d6, and so on. This is a potential 55d6 damage, but RCFG limits this to 20d6 for a fall of 60 feet or more (the Beta Playtest rules limited to 10d6 for 40 ft.+). So, Smaug takes 20d6 for the fall (20 to 120 damage), some additional damage for the surface fallen onto (let's say 4d6, or 4 to 24 damage), and then is in the water.....which is so inimical to him that cutting the bridge foils him. Tolkein notes that the lake would put out his fire.....and I would say that was probably sufficient to finish him off.
There are several other ways in which you can also gain a bonus to hit, to damage, to your chance of a critical, to AC, etc., based upon how you choose to fight, and what you choose to do. All of this uses hit points, but damage dealt (like damage you can take) becomes a variable of character (and player) skill.
RC