cheat sheet
Quick Reference
A condensed version of the guide. You can use it as a checklist while you build, and open a chapter when you want to go more in depth.
Identity
Full chapter- Write one sentence about the creature before you open the statblock. Test every choice against it.
- Fill in size, type, movement, and senses first. They follow from the concept and need no balancing.
- Pick the role this creature will play in combat, and let it decide where the numbers bend. Click a role to see how its stats compare to the CR baseline.
- Count turns. One monster acts once per round, a party acts four or five times.
Hides, strikes, and hides again. Hits harder than the CR baseline, with lower HP and AC in exchange.
baseline CRabovebelow
Above the CR baseline: damage per round, special abilities. Below: AC and save DC, hit points. Other stats at the baseline.
The numbers
Full chapter- Deviate from the baseline to fit the role, but adjust. More damage means fewer hit points or lower AC.
- If every stat sits above the baseline, that's not a tough monster, that's a higher CR. Raise it.
- Cross-check: average the defensive CR with the offensive CR. It should match the CR you wrote down.
Offense & defense
Full chapter- The math is based on a three-round fight. Balance the average damage of the creature's three best rounds, not its single biggest one.
- An effect that hits two or more characters counts double. Budget it at half the damage-per-round number.
- A recharge ability may spike above budget if the normal rounds stay under it. Give the spike a visible tell.
- Make save DC rely on just one ability. If an attack also poisons, restrains, or knocks prone, lower its damage.
- A solo boss needs about 25% more damage, three legendary actions per round, legendary resistance 3/day, and ideally a few allies.
Traits and actions
Full chapter- Three actions is usually enough, five is the maximum. A fight lasts three to five rounds.
- Abilities should force a decision. Flat extra damage doesn't force any.
- Telegraph big abilities a round early, then pay off.
- Match damage types to the concept.
- Insert attacks and saves with the editor's Attack line and Saving throw line options, so the numbers recompute when the stats change.
- End with one line of behavior: how it opens, what it protects, when it runs.
Avoid
Full chapter- A longer fight needs more threat, not more hit points.
- Don't take the same player's turns away round after round.
- Cut abilities, or split them over two monsters.
- Bring minions, or the full legendary package.
- Immunity to the party's favorite tricks. Build lightning rods for them instead.
Playtest
Full chapter- Put the statblock next to its CR row, and next to a published monster of the same CR.
- Check the extremes: its best possible round shouldn't delete a character, and a stunned round one shouldn't delete the monster.
- Encounter check: possibly deadly when the monsters' total CR is more than ¼ of the characters' total levels (levels 1–4), or ½ (level 5 and up).
- Adjust during the fight, edit the statblock the same evening, and keep the version that played better. Duplicating in your library is free.
The formulas and roles are adapted from the Lazy GM's 5e Monster Builder Resource Document (CC-BY 4.0) and Paul Hughes's 2024 Monster Manual analysis. Full credits in Sources and attribution.