This guide would not have been possible without the amazing people listed below. It consolidates monster-design knowledge the D&D community developed over many years, and the thinking belongs to its creators. I've just organized it, connected it to Monsterbrew's editor and kept it 2024-focused. If this guide was useful, their full works go deeper than I do here, and the paid ones are worth every penny (or copper).

The Lazy GM's 5e Monster Builder Resource Document

The benchmark table, quick formulas, monster roles, lightning rods, the lazy encounter benchmark, and the ten reusable monster features are adapted from this document, which is generously released under a Creative Commons license:

This work includes material taken from the Lazy GM's 5e Monster Builder Resource Document written by Teos Abadía of Alphastream.org, Scott Fitzgerald Gray of Insaneangel.com, and Michael E. Shea of SlyFlourish.com, available under a Creative Commons Attribution 4.0 International License.

The same material appears, expanded, in their book Forge of Foes, which covers building, customizing, and running 5e monsters in far more depth than this guide.

Blog of Holding: the 2024 monster math

The 2024-specific numbers come from Paul Hughes's statistical analysis of every monster in the 2024 Monster Manual, published as "The 2024 Monster Manual on a business card" on Blog of Holding: hit points ≈ 15 + 15 per CR, damage ≈ 7.5 per CR, the sharp scaling break above CR 20, the ~25% legendary damage premium, and the finding that 2024 monsters hit about 50% harder than 2014's. The business-card guidelines are released under CC-BY 4.0. His 2014 predecessor card is a community classic, and the full post is the best available look at how the revised Monster Manual is actually built.

Alphastream: the 2024 creation process

The step-by-step framing (concept before math, offensive/defensive CR averaging, keeping statblocks to three-to-five actions, single-ability DCs, and comparing against published monsters) is paraphrased from Teos Abadía's article "How to Create a Monster for Revised D&D 5e (2024)" on Alphastream.org, with the author's video analysis of the 2024 Monster Manual underpinning much of the community's math (including the Blog of Holding work above). Alphastream is one of the most consistently excellent sources on 5e adventure and encounter design.

System Reference Document

Monster names and official statistics referenced throughout the guide, and the SRD monsters in Monsterbrew's library, come from Wizards of the Coast's System Reference Document:

This work includes material from the System Reference Document 5.2.1 ("SRD 5.2.1") by Wizards of the Coast LLC, available at https://www.dndbeyond.com/srd. The SRD 5.2.1 is licensed under the Creative Commons Attribution 4.0 International License, available at https://creativecommons.org/licenses/by/4.0/legalcode.

Further reading

Beyond the direct sources, the community's monster-design conversation is rich and ongoing: Keith Ammann's The Monsters Know What They're Doing (monster tactics), the Level Up: Advanced 5e Monstrous Menagerie (Paul Hughes's own monster design), and Sly Flourish's Return of the Lazy Dungeon Master (the preparation philosophy the "lazy" tools come from) are all excellent next steps.

Found an error in this guide, or a source I should credit? Open an issue. Attribution matters to me.