“Beast Builder” CR Calculator for Rangers and Druids

The Beastmaster Ranger has long been plagued by the squishy-ness of its animal companion. While the Revised Ranger tackled some of the action economy issues for the Beastmaster, it did not address the underlying issue: that the beast is supposed to be the highlight of the show.

Shapeshifting Druids are also plagued by unimpressive beast stats, but from more of a flavor perspective. A Druid who has built their backstory around being raised by wolves can shapeshift into a wolf, then a dire wolf, then a winter wolf, then what? A T-Rex? It would comport a lot more with the flavor of the Druid to be able to keep that same form as it become the more powerful “alpha” wolf.

The Solution: “Beast Builder”

The elegant solution is to scale the beast’s stats until they are in line with your class level. This makes the beast (companion or form) effective without rocking the boat on the other class features.

What’s elegant is not always easy to implement. I input all the beast stats into a table:

Beast Stats

Using those stats, I reverse-engineered the Armor Class (AC), Hit Points (HP), Attack Bonus, and Damage of the beasts in the world of Dungeons & Dragons, while controlling for all the other abilities the beasts have.

Scaling Damage

In order to determine the damage for each beast, I had to reduce it to a specific damage total. I accomplished this by calculating the damage a creature could do in three rounds, while accounting for their types of attacks and special abilities. This damage calculation appears on a separate tab.

Here we see the robust suite of the giant scorpion:

Giant Scorpion Attack

Damage for attacks and abilities are both adjusted for the likelihood of their occurrence. For example, the average poison damage is only 15 per round, even though it’s 4d10 damage, because of the DC 12 save against the poison.

Checking Our Work

Thankfully, the Dungeon Master’s Guide provides Monster Statistics by Challenge Rating (page 274). We can reverse-engineer these guidelines to check our work against the beast CR scaling. This gives us a bicameral calculation that makes sure our CR adjustments aren’t too swingy.

“Beast Builder” CR Calulator

Step 1: Pick a Beast

Pick your beast and get some basic stats on it.

Beast Builder Step 1

Step 2: Pick a CR

Pick a new CR. The Beast Builder will give your new beast stats. It’s that easy.

Beast Builder Step 2

Step 3: Tweak Your Stats

You can further adjust your stats. Since there are a lot more low-level beasts than high-level beasts, the numbers can get swingy when you goof around and make a CR 8 bat. Use this step to keep those adjustments true. You can also make little tweaks to your beast stats in this phase, crafting the beast that’s the best fit for your character. These adjustments control for other abilities while scaling the Armor Class (AC), Hit Points (AC), Attack Bonus, and Damage in accordance with the Monster Statistics by Challenge Rating table on Dungeon Master’s Guide (page 274).

Beast Builder Step 3


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s