Quickleaf
Legend
Here's how it works:Ok I rolled my HP, Hit Points: 2d8+4 15.
One other question using the Worlds Without Numbers method would you just reroll for 2nd level HD and up then add max for first on each new level? I just ask because if you re-roll everything including 1st level then it does not work to take that method. I looked it up and at second level you only have a 50% chance to beat your 1st level HP.
At 1st level you have 10 hit points (artificer with Con +2).
At 2nd level, you opt to do the WWN roll for Hit Points. You roll 2d8+4. Let's say you get a total of 9. Because that's less than your current maximum Hit Points of 10, you would just add 1+CON mod to your hit points. So you'd add 3 hit points, bringing your HP to 13.
At 3rd level, you opt to do the WWN roll for Hit Points again. You roll 3d8+6. Let's say you get a total of 18. Because that is greater than your current HP, your new Hit Points become 18.
Basically, it's a way to have a little old school variability, but it causes really bad rolls to even out in the long run, so (if you can keep your PC alive long enough) you don't get totally screwed by one or two bad rolls over the length of a game spanning several levels.