How do you really determine monster ability scores?

[Grazzt]

The important first step is realizing that you don't need to actually care about the ability scores... then make them something appropriate. It'll make some people happier if the math is even remotely close, but the fudge factor is rich and creamy in this edition.

This too. Ability scores really affect few things on the monsters now. HP, skills, and initiative. That's about it. They dont affect attack rolls at all, and have very little impact on defenses and even damage rolls.

Defenses, sure it says, adjust by +/- 1 for every 2 points over the avg (13 + 1/2 level) an ability score is, but even the MM doesnt follow this. Its a good point of reference, but then you tweak the scores up or down from that baseline as you see fit.

 

[Lizard]

This.

And yep, there has to be some balance on the DM's part obviously. Ya wouldnt wanna design a Level 1 monster with AC 45, and all defenses set to 51, for example. You could I guess, but Im thinking the PCs would have a very hard time hitting it at all.

Monster design in 4e is definitely more like the old days (pre-3.x). Just concept your monster, figure out what you want it to do, and what you need to give it to make it happen. No more worrying about spending all its skill points, or including synergy bonuses, or "did I assign enough feats?"

Sounds too easy. There has to be a trick.

 

[Draloric]

In other words if you stuck to 13 + one-half the monster’s level for one of each pair of ability scores (STR and CON, DEX and INT, WIS and CHA) with the exception of one of those being 16 + one-half
the monster’s level, you should have defenses equal to:

12 + the monster’s level
12 + the monster’s level
13 + the monster's level (this one corresponds to the monsters main ability for attacks)

Thats what the average should be. Now that you know that, adjust the ability scores for whatever fluff you want, and keep in mind how that will effect your defenses relative to the average. And remember, the only ability scores that need to be in line are one of each pair. The others from each pair can be any ability score lower then the other.

I think you've just solved my problem with this, while illuminating some of the brilliance of 4th Edition monster design. Thanks, ForbidenMaster; somehow the way you've explained it makes it seem much clearer.

On another note sprung from this thread, Scott seems to be right too: I've noticed several of the MM monsters don't seem to follow these guidelines very strictly. (I'm not suggesting this is bad design, by the way.) I wonder what other parametres (weighing higher-level damage expressions against sub-optimal defences [?], for example) might be built in to keep monsters roughly in-line with expected PC levels (beyond playtesting, that is...)

 

[Grazzt]

Sounds too easy. There has to be a trick.

You would think after 3.x's design rules

I'm glad they finally realized (or rather got back to the pre-3.x days) that it's ok for monsters to be able to do stuff PCs cant, and it's ok for them to be built on a different set of rules/guidelines.

 

[Spatula]

I'm glad they finally realized (or rather got back to the pre-3.x days) that it's ok for monsters to be able to do stuff PCs cant,

Not that that was ever not the case...

and it's ok for them to be built on a different set of rules/guidelines.

Unfortunately they didn't bother to tell us what those rules / guidelines are. Or rather, they gave us one set, then used another to make many of the monsters in the MM. The DM toolbox area of the DMG is sadly lacking in that regard.

 

[Xyl]

The actual rule is "make something up, then playtest".

If you don't have time to playtest, the guidelines in the DMG are pre-playtested.

 

[keterys]

The rules and guidelines seemed pretty clear to me, and the DMG toolbox seemed quite good.

Many DMs who -could not have previously- shouldn't have any problems whipping up something balanced and cool on the fly.

Score.

 

[Grazzt]

The rules and guidelines seemed pretty clear to me, and the DMG toolbox seemed quite good.

Many DMs who -could not have previously- shouldn't have any problems whipping up something balanced and cool on the fly.

Score.

Agreed. Definitely seem clear to me. They are just guidelines. Not hard/fast rules like 3.x had for monster/npc design.

Use the formulas to find your baseline, then adjust up/down based on what you want (or check a similar monster in the MM to get an idea).