# What does the DMG mean by 'points' in monster building?

On page 274 (DMG), the following is found for defensive CR (with an equivalent for offensive later on):

If your monster's AC is at least two points higher or lower than [its hit points suggest the AC should be], adjust the challenge rating suggested by its hit points up or down by 1 for every 2 points of difference.

What does it mean by 'points' here?

Take an example where a creature's AC is 16, but it has 36 HP. It's 'hit point CR' is 1/4, but its 'AC CR' is 8.

Do you count $9$ rows up on the table to get $-4$ (and therefore CR 4), or calculate $8-\frac 1 4 = 7 \frac 3 4$ to get $-3$ (and therefore CR 3)?

• Can you revise the question? At first read, it sounds as if you're asking what "points" are in terms of "points of difference," in this case the difference in Armor Class, but you're actually asking how to move the Challenge based on AC, and Challenge isn't described using the word "points" in the quoted section. – Polisurgist Jun 9 '16 at 20:25
• @Polisurgist I'm not sure I understand your confusion. I'm asking whether 'points' means 'CR points' or 'rows on the table'. – Ladifas Jun 9 '16 at 20:38

You seem to be misquoting the DMG, which might be where the confusion is coming from.

The actual quote is (bold mine, for emphasis):

If your monster's AC is at least two points higher or lower than that number, adjust the challenge rating suggested by its hit points up or down by 1 for every 2 points of difference.

"That number" being AC in this case.

For your example, the defensive CR is 1/4, and it's assumed to have an AC of 13. But your AC is 3 points higher, so you would go up one CR (it's +CR for every 2 points; since yours is only 3 points higher, we round down).

The final defensive CR for your creature is 1/2. The AC doesn't contribute its own CR to the calculations: the base defensive CR is based on HP, not AC. AC modifies the HP-based CR, yes, but it's not a main factor in defensive CR.

• So the points of difference are actually points of AC? – Ladifas Jun 9 '16 at 21:55
• Yes, that is correct. – Christopher Jun 9 '16 at 21:58