At high CR, doesnвЂ™t it look like there is an inverse correlation between damage and hit points? At CR 19 and 21, for instance, where damage is high, hit points are low. I admit, something about the chart above gave me pause.

Given the fact that the D&D designers have frequently mentioned three rounds as their target combat length, this seems plausible. To me it kind of looks like the average monsterвЂ™s hit points is intended to be 3x the average monsterвЂ™s damage (or, to put it another way, each monster should survive exactly three rounds of hits against one of its peers). Take a look at this chart where I graph median hit points (blue) and median damage x 3 (red). HereвЂ™s one interesting thing about hit points and damage: they have a very strong relationship, especially at low level. The remaining values, average damage and hit points, are a bit hairy, because theyвЂ™re not nice, neat linear graphs. I did attack bonus, DC, and AC first because they were the easy ones. Therefore, if we say вЂњ+-3 AC based on monster conceptвЂќ weвЂ™d be allowing all but a few outliers. The average variance is 1.65: 50% more than in attack and DC. So on our final rules, weвЂ™ll say, вЂњ+-2 DC based on monster concept.вЂќДЇrom the scatter plot, Armor Class also looks like a fairly neat linear graph.Д®xpressed as a formula, this is very tidy: AC = 13 + 1/3 CRДЇrom looking at the scatter plot, you can see that there will be a higher variance in AC than there was in attack and DC. Variance is also the same for DC as it is for attack bonus. In the following scatter plot, blue XвЂ™es are DC, and green triangles are attack bonus. In fact, its graph is nearly identical to the attack bonus (nearly every monsterвЂ™s DC is their attack +7). So we could say, without doing too much violence to the Monster Manual data, something like, вЂњBased on your monster concept, you may add or subtract up to 2 points from the attack bonus without affecting its CR.вЂќДifficulty Class is similarly neat. And, as weвЂ™ve proved in previous steps, there is no correlation between high/low attack bonus and any other monster stat. In other words, monster attack bonuses tend to be a little more than one point away from the average. We donвЂ™t want to adjust anything later! WeвЂ™ll just look at our Monster Manual data and see how much variation there tends to be from the average monster accuracy.ДЇor our attack bonuses, the average variance (which is a statistical calculation for determining how closely grouped numbers are) is low: 1.22. How much leeway do we have to adjust the attack bonus up or down based on our concept? The DMG advice is to adjust as much as you want, you can always adjust the CR later. ThatвЂ™s the way that the linear values on the attack graph work out, and the way IвЂ™ve graphed it. For the purposes of drawing graphs, think of them as negative numbers instead of fractions: CR 1/2 is really 0, CR 1/4 is -1, CR 1/8 is -2, CR 0 is -3.

While the DMG graph is arbitrary and inaccurate, actual monster design shows signs of being very carefully put together.ДЄ note about CRs below 1: These complicate things. So tidy! ItвЂ™s almost as if the designers designed it that way! Hint: I think they did. (For comparison, the red line is a plot of the Dungeon MasterвЂ™s Guide suggested attack bonuses.)ДЄs you can see, the scatter plot shows us a nice, straight, easily graphable best-fit line. HereвЂ™s a scatter plot of the attack bonuses of all the Monster Manual and MordenkainenвЂ™s monsters.

Therefore, we can examine each monster stat separately without having to consider the others at the same time. For instance, you might expect that a monster whose AC is high for its Challenge Rating should have lower hit points, attack bonus, or damage output to compensate. If you prefer everything calculated out, hereвЂ™s a one-page version with more explanation and an exampleДЇirst of all, to reiterate what I learned in previous posts:ДЎ) real monsters have fewer hit points and do less damage than those created by the DMG chart, and are more accurateДў) there is no significant correlation between any major monster stat (HP, AC, attack bonus) and any other stat. HereвЂ™s the finished business card! The rest of this post will explain how we came up with it.

Monster manual dnd 5e