Monster Advancement (Table 2-1)

[Syntaxis]

I'm having some serious trouble understanding the point of table 2-1 in the Bestiary. Mathematically, it makes zero sense to me and doesn't seem to have any logic behind it. I can advance a monster just fine without it, but I want to know what it's trying to accomplish. The Hit Point Change column makes no sense, and doesn't match up to what the CRs should be for adding that much HP. The rest of the chart doesn't add up either, with no reasoning behind the seemingly arbitrary increases to AC and Damage. Either I'm an idiot or this chart is terrible. Could someone please enlighten me to the purpose of this thing?

[Syntaxis]

Nothing?

[Eltacolibre]

In the bestiary they state, its the average change. Which varies from creature to creature. See p. 296 of the bestiary stage 5 statistics for more details.

[KestrelZ]

It is supposed to be a quick, averaging alternative to quickly place a variable monster on the fly. As it is shorthand, the math is wonky, and likely shouldn't be done to adjust more than a few CR levels.

Really, you would only use it if you had random encounter tables that had a wide range of CR encounters for sandbox adventures. Add to it a party that always challenges EVERYTHING, and you may want to adjust some CRs to either provide an actual challenge, rather than a speedbump or a total party kill.

It should also be ignored if you have preplanned the encounter and had time to actually adjust a monster with added (or removed) hit dice and features.

The chart seems to be adding an average for a d10 hit die creature with no CON bonus. I agree that the attack and damage bonus portion of the charts are rather confusing, yet if someone gets them wrong - they are random encounters. Players will likely never know you did it wrong.