Goodman Games

One thing I still have a lot of trouble with is making sure the monsters I've created are of a threat level appropriate to the characters. A lot of times when I'm running a game, my monsters don't actually have any hit points. I just keep track of how much damage the characters have done, and the monster dies when the battle has been dramatic enough. That obviously doesn't work well when creating monsters for publication.

I know there aren't any hard and fast rules governing what makes a monster a certain CR. I usually find a monster in the SRD of the CR I'm looking for and change some of its special abilities, but I can't help but feel there has to be a better way. So how does everyone else go about creating new monsters and making sure they are appropriate to the characters, or even that its CR is appropriate to the abilities you've given it?

Well, the book recommends running a "test party" against it. I have to say, though, I've NEVER done that.

The book also has some guidelines on determining proper AC, HD, attack bonus, and stuff like that...I ususally refer to those when I'm done or when I'm stuck, but not all the time.

What I most often do is create my "dream" monster, with all the bells and whistles. Then I find three critters (one of the same type and two others) of the target CR I'm looking for, and start comparing. I tweak HD up or down (usually up), check save DCs, consider damage output, look at number of special abilities...that sort of thing.
There's a lot of compare/contrast..."The aboleth has X and Y, but I'm a whole lot tougher and can do Z, still, that's not quite equal..."
Which is a long way to say that I "eyeball" it.

Then, most importantly, I playtest the damn thing. Not by itself, as part of the scenario. I keep notes on how it plays out "live."

The gnomish lancer (mark I) and gnomish marksman from Castle Whiterock got some serious hardness upgrades after a playtest where they got WORKED, and it seemed to really give them the "oomph" they needed.

The fissure wasp scout, however, was almost TOO tough 'cause it took a full clip from a repeater crossbow and kept coming, so we had to consider scaling it back. Ended up not doing so, however...it's just one tough bug.

We also sometimes get to use Aeryn "Blackdirge" Rudel as a monster editor, and that man is my monster-creating god, much like how Jeremy Simmons is the god of maps (which is MUCH better than being the lord of the dance).

Really, there's no perfect formula for making challange appropriate monsters. Playtesting certainly helps, but not every group is the same, or uses the same tactics, so you can get wildly different outcomes with different groups of similar characters.

Like Jengenritx does, when I create a new monster, I compare my finished product to a couple of similar monsters from the MM. For example, if I make a CR 3 corporeal undead, then I'll compare it to a wight (also CR 3) to see if I'm in the ballpark, From that point I'll add or subtract special abilities, hit points, AC, etc., until I feel I have the right mix.

In the end, it comes down to a gut feeling, which is usually right, but then again, I've slaughtered whole parties with a new monster I thought was a "cake-walk".

Fell free to post one of your creations. I'd be happy to help you get it as close as possible to the desired CR.

BD