Rules Index | GM Screen


Monster Creation

Source Pathfinder RPG Bestiary pg. 290
Creating a monster is part science and part art. While most monsters follow a general pattern of their overall power and abilities as related to their Challenge Rating (CR), there are many exceptions. Some monsters, for example, have significantly more hit points or a higher AC than the average for their CR, but make up for this advantage by being weak in other areas. Other monsters have significantly higher average damage, but have a lower attack bonus.

The following guidelines are provided to assist in monster creation and to help balance a creation for its CR.

Step 1: Concept

Source Pathfinder RPG Bestiary pg. 290
The first step in creating a new monster is to define its concept and role in the game. Generally, this involves picking the monster’s CR, type, physical appearance, and manner of fighting. Once you have these basic pieces of information, you should find a number of similar monsters of the same type and roughly the same CR for comparison purposes.

Step 2: Target Statistics

Source Pathfinder RPG Bestiary pg. 290
Once you have a creature’s type and CR determined, use Table 1–1 to determine its approximate statistics by CR. These values are a rough guideline only. You will notice that many of the existing monsters in this book do not follow these guidelines exactly. Most monsters excel in one of these areas, usually in the amount of damage dealt, but lag in one or two other areas to help balance them out. When referring to Table 1–1, keep the following points in mind.

CR: This is the approximate CR of the monster. This number might change as design progresses.

Hit Points: This is the approximate hit point total for the monster. Note that creatures with particularly high Armor Classes or saving throws, or a number of resistances, might have a lower number. Outsiders and constructs typically have lower hit point totals.

Armor Class: This is the average Armor Class for a creature of this CR. When it comes time to design the creature’s protections, keep this number in mind. Creatures with hit points above the average often have lower Armor Class values to compensate.

High Attack: This is the average total attack bonus for a creature of this CR. This value is for creatures that are primarily melee or ranged combatants. Creatures with a higher than normal average damage typically have a lower attack value to compensate.

Low Attack: This is the average total attack bonus for a creature of this CR that does not rely upon melee or ranged attacks to deal damage. This includes most creatures that rely on spells and spell-like abilities in combat.

Average Damage: This is the average amount of damage dealt by a creature of this CR if all of its attacks are successful. To determine a creature’s average damage, add the average value for all of the damage dice rolled (as determined by Table 1–5) to the damage modifier for each attack. A creature that relies on melee or ranged weapons in combat should have average damage within the range of high and low damage. A creature with higher than normal attack bonuses will often deal lower damage, while a creature with lower than normal attack bonuses will often deal higher damage. Primary Ability DC: This is the average difficulty class (DC) for any spells, spell-like abilities, and special abilities (such as breath weapons) possessed by a creature of this CR that relies on such attacks in combat. If an ability is particularly powerful, it might have a lower DC to compensate.

Secondary Ability DC: This is the average DC for spells and special abilities for a creature that does not rely on such attacks in combat. Generally, a DC should not be lower than this number.

Good Save: This is the average saving throw bonus for a creature of this CR if the saving throw is one of the creature’s good saving throws.

Poor Save: This is the average saving throw bonus for a creature of this CR if the saving throw is one of the creature’s poor saving throws.

Table 1-1: Monster Statistics by CR

Average Damage
CRHit PointsArmr ClassHigh AttackLow AttackHighLowPrimary Ability DCSecondary Ability DCGood SavePoor Save

Step 3: Hit Dice

Source Pathfinder RPG Bestiary pg. 290
The next step in creating a monster is to determine the approximate number of Hit Dice it has. Hit Dice determine a wide variety of other statistics, including the creature’s feats, skills, hit points, attack bonuses, and special ability DCs.

A creature’s total number of Hit Dice depends on a number of factors, but the two most important are its CR and its type. Table 1–2 lists the average number of Hit Dice for each creature type, depending on its CR. While many of the monsters in this book are close to these values, some are not. This is because they have higher or lower average hit points to balance out their Armor Class or resistances.

Table 1-2: Creature Hit Dice

Challenge Rating
Creature Type1/21234567891011121314151617181920
Magical Beast1234568910121314161819202123252831
Monstrous Humanoid1234568910121314161819202123252831

Step 4: Size

Source Pathfinder RPG Bestiary pg. 290
Now that you have the creature’s average statistics, it’s time to pick its size. Most creatures range in size from Small to Huge, but other sizes are not uncommon. A creature’s size sets a baseline for its physical ability scores and its natural weapon damage (as noted in the Natural Attacks description in the Universal Monster Rules). You should pick a size that fits well with the creature’s intended role in the game and Challenge Rating. If you decide to give a creature an unusual size for its CR or HD, you should justify the unusual choice in the monster’s description to account for the discrepancy—in most cases, such unusually sized monsters should be highly magical in nature. See Table 1–3 for more information on creature sizes and expected scores.

Minimum/Maximum CR: These values list the minimum and the maximum challenge ratings a creature of the indicated size should fall between.

Base Str, Base Dex, Base Con: These list the average scores for a creature of this size. Your specific monster’s Strength, Dexterity, or Constitution might vary greatly from these numbers, but if they do, you should pay close attention to how these variances affect its other statistics.

Table 1-3: Size

SizeMinimum CRMaximum CRBase StrBase DexBase Con

Step 5: Abilities

Source Pathfinder RPG Bestiary pg. 291
Once you have determined a creature’s size, type, and Hit Dice, it’s time to move on to its ability scores. The bonuses granted from these ability scores should increase a creature’s hit points, attack bonuses, and saving throws to the approximate values presented on Table 1–1.

A creature’s physical ability scores (Strength, Dexterity, and Constitution) should be relatively close to the base values presented on Table 1–3, depending on its size. Creatures with a few Hit Dice but a high average hit point total should have a higher than normal Constitution.

A creature’s mental ability scores (Intelligence, Wisdom, and Charisma) are largely defined by the creature’s concept. The base for all of these abilities is 10. Creatures that rely on spells and spell-like abilities in combat should have one mental ability score that stands out (usually Charisma). Creatures incapable of speech have an Intelligence score of 2 or lower. Unintelligent undead, constructs, oozes, plants, and vermin rarely have an Intelligence score.

Step 6: Skills and Feats

Source Pathfinder RPG Bestiary pg. 292
Using Table 1–4, determine how many skill ranks your creature has based on its type and Hit Dice. Assign these ranks as determined by the creature’s concept. A creature’s class skills are determined by its type (see the creature types). Creatures with a low Intelligence typically only have ranks in Dexterity- and Strength-based skills.

After you have assigned skills, it’s time to assign the creature’s feats. Each creature with an Intelligence score receives a number of feats equal to 1 + 1 per every 2 Hit Dice after the first (so, 1 at 1 HD, 2 at 3 HD, etc.). A creature must qualify to take a feat as normal. See Table 1–6 for a quick feat calculation chart.

Table 1-4: Creature Statistics by Type

TypeHit DieBase Attack Bonus (BAB)Good Saving ThrowsSkill Ranks*
Aberrationd8HD x 3/4 (Medium BAB)Will4 + Int mod per HD
Animald8HD x 3/4 (Medium BAB)Fort, Ref2 + Int mod per HD
Constructd10HD (Fast BAB)2 + Int mod per HD
Dragond12HD (Fast BAB)Fort, Ref, Will6 + Int mod per HD
Feyd6HD x 1/2 (Slow BAB)Ref, Will6 + Int mod per HD
Humanoidd8HD x 3/4 (Medium BAB)Varies (any one)2 + Int mod per HD
Magical Beastd10HD (Fast BAB)Fort, Ref2 + Int mod per HD
Monstrous Humanoidd10HD (Fast BAB)Ref, Will4 + Int mod per HD
Oozed8HD x 3/4 (Medium BAB)2 + Int mod per HD
Outsiderd10HD (Fast BAB)Varies (any two)6 + Int mod per HD
Plantd8HD x 3/4 (Medium BAB)Fort2 + Int mod per HD
Undeadd8HD x 3/4 (Medium BAB)Will4 + Int mod per HD
Vermind8HD x 3/4 (Medium BAB)Fort2 + Int mod per HD
* As long as a creature has an Intelligence of at least 1, it gains a minimum of 1 skill point per Hit Die. Creatures with an Intelligence score of “—” gain no skill points or feats.

Step 7: Other Statistics

Source Pathfinder RPG Bestiary pg. 292
Using Tables 1–1, 1–4, and 1–6, you can now determine many of the creature’s other statistics.

When building a creature’s Armor Class, start by adding armor, shield, and natural armor bonuses to its Dexterity modifier. If a creature does not wear armor, give it a tougher hide to get it near its average AC. Remember that creatures with higher hit point totals might have a lower Armor Class, whereas creatures with fewer hit points might have a higher Armor Class. If a creature’s Armor Class deviates from the average by more than 5 points, it might not be the right CR.

When determining a creature’s attack bonuses, refer to the guidelines from Table 1–1 based on the creature’s CR. If the bonus is too low, consider increasing the creature’s Strength or Dexterity, or increasing the amount of damage it deals to above the average. If the bonus is too high, consider decreasing the creature’s Strength or Dexterity, or decrease the amount of damage it deals. If this value is significantly different, and the creature is intended to rely on melee or ranged attacks, consider adjusting the creature’s CR.

Use Table 1–5 to determine the number of damage dice, combined with damage bonuses, that the creature needs to reach the average damage for its CR. The creature might need additional or more damaging attacks to approach the average. Remember that creatures that primarily deal damage with other abilities, such as spells, do not need to meet the average damage for their attacks. You can also use Table 1–5 to determine a creature’s average hit points. Remember that PC class levels provide the maximum number of hit points at 1st level.

Repeat this process for a creature’s saving throws. If the saving throws are too high, consider altering the ability scores on which they are based.

When determining a creature’s speed, first decide if it has any alternative modes of movement, such as burrow, climb, fly, or swim. Most Medium creatures have a base speed of 30 feet. Quadrupeds and Large creatures increase this by 10 feet each. Smaller creatures decrease this base speed by 10 feet. If a creature is particularly fast or slow, modify the base speed by 10 feet. Burrow and climb speeds are usually half a creature’s base speed, while flying speeds are roughly double. Remember to give a creature the appropriate skills for any unusual movement methods.

Table 1-5: Average Die Results

Die TypeAverage Result*

Table 1-6: Statistics Summary

HDFast BABMedium BABSlow BABGood SaveBad SaveFeats

Step 8: Special Abilities and Qualities

Source Pathfinder RPG Bestiary pg. 292
Monsters are different from characters in that they can have all sorts of different special abilities and qualities. Each of these is tied closely to the creature’s concept, allowing it to fill a specific role in the game. For examples, look at monsters in this book. Monsters should use abilities from the Universal Monster Rules whenever possible, instead of creating new yet similar abilities—when you do create new abilities, use the Universal Monster Rules as a template for how to present and create the new abilities.

Most special abilities that cause damage, such as breath weapons, give a save (Fortitude, Reflex, or Will depending on the ability). The DC for almost all special abilities is equal to 10 + 1/2 the creature’s Hit Dice + a relevant ability modifier (usually Constitution or Charisma depending on the ability). Special abilities that add to melee and ranged attacks generally do not allow a save, as they rely on the attacks hitting to be useful.

Special senses and resistances to certain energy types are common in creatures of CR 5 and lower. Damage reduction, energy immunities, and regeneration are more common in creatures above CR 5. Spell resistance and immunities become more common above CR 10. As a general rule a creature’s spell resitance should equal its CR + 11.

Step 9: Treasure

Source Pathfinder RPG Bestiary pg. 293
A creature should have an amount of treasure appropriate to its CR. See Table 1–7 for a list of treasure totals based on CR. For some creatures, their treasure consists of the loot from their recent meals strewn across their lairs, while for others it consists of a greed-fueled hoard or even gear it uses in combat. Make sure to account for any weapons or armor that the creature is using, as determined by step 7.

Table 1-7: XP and GP Values by CR

CRXPSlow GPMedium GPFast GP
1/850 XP20 gp35 gp50 gp
1/665 XP30 gp45 gp65 gp
1/4100 XP40 gp65 gp100 gp
1/3135 XP55 gp85 gp135 gp
1/2200 XP85 gp130 gp200 gp
1400 XP170 gp260 gp400 gp
2600 XP350 gp550 gp800 gp
3800 XP550 gp800 gp1,200 gp
41,200 XP750 gp1,150 gp1,700 gp
51,600 XP1,000 gp1,550 gp2,300 gp
62,400 XP1,350 gp2,000 gp3,000 gp
73,200 XP1,750 gp2,600 gp3,900 gp
84,800 XP2,200 gp3,350 gp5,000 gp
96,400 XP2,850 gp4,250 gp6,400 gp
109,600 XP3,650 gp5,450 gp8,200 gp
1112,800 XP4,650 gp7,000 gp10,500 gp
1219,200 XP6,000 gp9,000 gp13,500 gp
1325,600 XP7,750 gp11,600 gp17,500 gp
1438,400 XP10,000 gp15,000 gp22,000 gp
1551,200 XP13,000 gp19,500 gp29,000 gp
1676,800 XP16,500 gp25,000 gp38,000 gp
17102,400 XP22,000 gp32,000 gp48,000 gp
18153,600 XP28,000 gp14,000 gp62,000 gp
19204,800 XP35,000 gp53,000 gp79,000 gp
20307,200 XP44,000 gp67,000 gp100,000 gp
21409,600 XP56,000 gp84,000 gp126,000 gp
22615,000 XP70,000 gp105,000 gp158,000 gp
23820,000 XP88,000 gp132,000 gp198,000 gp
241,230,000 XP110,000 gp165,000 gp248,000 gp
251,640,000 XP138,000 gp208,000 gp312,000 gp

Step 10: Details

Source Pathfinder RPG Bestiary pg. 293
Now that you have all of the creature’s statistics sorted out, it’s time to fill in all the details—such as name, alignment, space, reach, environment, and ecology—as you see fit.