So, I was looking at the description of Toughness from Design & Development: Feats, and something jumped out at me. I had been assuming that Fourth Edition would work similarly to Star Wars Saga Edition, with a static number of hit points at 1st-level and then an increase at every level after that. That's how Toughness works in SWSE, but it's not how Toughness works in Fourth Edition. Here's the feat description:
Toughness
Tier: Heroic
Benefit: When you take this feat, you gain additional hit points equal to your level + 3. You also gain 1 additional hit point every time you gain a level.
That means that, at 1st-level, Toughness grants 4 hp, not 3. Or in other words, at least as far as Toughness goes, 1st-level grants both a kicker (+3 hp), and the ordinary hit point that any level does (+1).
We can try to infer the mechanics by taking the example from Design & Development: Death and Dying of a 15th-level fighter with 120 hp, and applying some of the speculations that Steve Schubert implied were "on the right track" in the podcast - an initial boost and static hit points at each level after that. Here's my math:
Let's assume that a 1st-level Fighter gets a first level "kicker" of 30 hp. Let's further assume that he gains 5 hp per level after that. If we also give him a +1 CON bonus (12 or 13 CON), that means 6 hp per level. Extrapolating out, that gives:
1st - 36 hp
2nd - 42 hp
3rd - 48 hp
4th - 54 hp
5th - 60 hp
6th - 66 hp
7th - 72 hp
8th - 78 hp
9th - 84 hp
10th - 90 hp
11th - 96 hp
12th - 102 hp
13th - 108 hp
14th - 114 hp
15th - 120 hp
16th - 126 hp
17th - 132 hp
18th - 138 hp
19th - 144 hp
20th - 150 hp
21st - 156 hp
22nd - 162 hp
23rd - 168 hp
24th - 174 hp
25th - 180 hp
26th - 186 hp
27th - 192 hp
28th - 198 hp
29th - 204 hp
30th - 210 hp
That's at least consistent with both the mechanics of the Toughness feat and the numbers in Design & Development: Death and Dying. Also, if you assume that they reverse engineered from the Hit Dice, it almost makes sense.
In Third Edition, a fighter had d10 hit dice. Tripling that, á la Saga Edition (ported over from that stage of 4E design perhaps?), gives the "kicker" number of 30. Further, the base "per level" of 5 hp is a somewhat logical "half max on a d10," or "average on a d10, rounded down." Normalizing the progression of extra hit points to include Level 1 simplifies the math, so you're not accidentally figuring it as: "Let's see, Level 15 fighter = 30 + 5 x 15...no wait, 5 x 14..."
Which I know I've done when calculating hit points in Saga...
Under this system, your first "logical" instinct is also "correct." It's also consistent with how Saga handles attacks and defenses in that a starting 1st-level character gets both the "kicker" and his "first-level" bonus.
Thoughts? Speculations on what it might mean for other classes?
Personally, I think the d4 base is history, but I could be wrong.