HP calculation with dragons question

[Trastone]

I understand adding the extra hit dice to calculate the hp, but I cannot seem to figure out the extra + after the hit dice....

example:

Base statistics:
Black Dragon: 4d12

Aged Dragon
Young Black Dragon: HP: 76 (8d12+24)

So, according to the chart you get base hit dice + 4, which in the case of the Young Black Dragon is 4d12+ 4D12 which is the 8d12, but where did the +24 come from...I cannot find it anywhere and I can't seem to find anyone else asking the question.

[Ughbash]

+24 is likely the con bonus x 8 (number of hit dice).

So if a Young Black dragon has a 16 con it would for each hit dice be 1d12 +3 so 8d12 +24. (If it has less then 16 con it may have toughness).

[Rathendar]

Con Bonus multiplied by Hit Dice.(which by your numbers above i will assume is a +3 bonus x 8 HD)

[Trastone]

Thank you!!! I knew I was overlooking something. It just wasn't quite spelled out clearly to me.

[Trastone]

Just to make sure I understand the whole process...

For the first hit die you get the full point value. So 12, then you can take the average for the subsequent hit dice which is 6 * the number of hit Dice, which is 18 for the black dragon, so a total of 30. You can also roll the dice for the dragon right.

For the Young Black Dragon then it is 12 + (7*6)or 42 which is 54, and then you multiply the Con modifier(+3) for the con of 17 with the count of hit dice 8 which results in 24. Add that with the 54 and it is 78....I'm still not coming up with the correct hit points. Where have I made the error, I'm assuming it is in the initial calculation..

Which means I probably messed up the black dragon also.

[Rathendar]

using average HD you use the .5 value in the multiplier. AKA (8 x 6.5 = 52) + (8 x 3 = 24) = 76.

Hope that helps.

[Trastone]

Okay...that is easy...Not sure how I got all screwed up. Must be something to do with PC's and them counting their first hit die as the full points....