D&D 5E (2014) Tidbit for monster design

[Sword of Spirit]

I came up with that factor by noting the game's math seemed to be centered around one monster against a party of four PCs, but it's possible the actual calculation uses something else that just happens to be close to 0.25. For example, if the actual calculation uses 0.65/2.5 = 0.26 then a base AC of 12 and a base AB of +4 fits the published XP values quite well. Why these numbers? Well, 0.65 is the base chance to hit, so our effective DPR would now include that factor. And 2.5 is the average number of rounds a monster tends to live for against a baseline party of four level appropriate PCs, so our effective HP is treated more like an effective HP per round.

I had a thought and wanted to share immediately in case anyone wants to make use of it before I get to it.

What if it's just x1/3, since combat is expected to last 3 rounds?

That might sound overly simple, but we know they oversimplify from the input form (they don't include initiative bonus at all, for example).

EDIT: That's not actually looking very promising.
@tomedunn do you have any other possibilities than 14/13 that might work for an exponential version? Playing around with some other things and realizing having more flexibility there might be useful.

 

[Steady Vane]

A couple other thoughts have just occurred to me after messing with the formulas as I was writing this. One is that stegosaurus stands out as a problem. The only formulas that can deal with it are your exponential one (which has a steeper slope, and is too high on the cyclops), and your linear one with a -1 rather than -2 (which somehow magically works for everything, even though, if I understand correctly, it relies on two approximations in its derivation). It fails on everything else. I'm starting to believe that maybe a mistake was made in the data entry for the stegosaurus when they were making Volo's Guide. In this kind of analysis, I'm loathe to dismiss something as an anomaly, as it could just as easily be evidence that the formulas are all wrong. But I'm at least considering the possibility. If the developer had entered a 36 instead of a 26, or a 9 instead of a 7, or a 15 instead of a 13 or a 96 instead of a 76, it would give us the listed CR 4. Going forward, I may flag the stegosaurus as a potential error in the published math and test out formulas that work on everything except the stegosaurus to see how they hold up with more complicated monsters.

One of the funny things about 5e is that it has come out how certain "iconic" spells do too much damage on purpose. They had a spell formula, and purposely ignored it for certain spells to make them more "fun" - fun meaning overpowered for their level.

If I recall correctly, this also applies to most Dragons in the CR calculations. They are flat out stronger than they should be for their CR level. Now this has not been stated, but presumably that choice would follow the same logic. They are iconic and should be more powerful to be "fun".

When it comes to spells, Fireball is the most notorious, but I think I recall people who did spell cleanups for 5e stating that there were one or two per spell level that were chosen as well, if simply not as well known.

All that to say, could the Stegosaurus be another such monster case, where it's simply more powerful than it should be, because it's an "iconic" monster?


Addendum: This is why I rely on averages when making 5e monsters, it tends to drown out the outliers. Tomedunn's blog has been a great source of such math crunching