All NPCs have two main stats: hit points and attack rating. An NPC's attack rating is how much damage it deals whenever it hits an opponent with a basic attack. And an NPC's hit points, like the player characters' hit points, are the measure of their mortality. However, NPCs are more vulnerable to death than player characters. When an NPC is reduced to 0 hit points, they die immediately.
Base stats: 2 HP, 1 Attack
Commoners are average creatures, like the everyday people and animals you meet. They don't usually pose a threat to the party, unless they hold some position of power or influence.
Farmers, merchants, artists, politicians, pets, and other average creatures are all examples of commoners. You should use these characters mostly for social interactions. They're not fighters, but they may defend themselves if necessary.
Most commoners are like extras in a movie: background characters who help to fill the world and give it life.
Base stats: 4 HP, 2 Attack
Minions are any tougher characters who could pose a threat to the party in an encounter, like a bear in the forest or rank-and-file members of the town guard. Most minions don't usually pose a big threat to the party by themselves, but they can be deadly in groups.
Some minions, like bandits, travel in small groups with their own agendas, while others act in service of a boss.
Minions can be very powerful, but they are more susceptible to the players' special abilities than bosses.
Base stats: 10 HP, 4 Attack
Bosses are special characters of exceptional power and importance. They are major characters who should each have a goal they are working toward, whether it's to take over a town, guard their dungeon, or simply to prey on adventurers. They should operate in the background and affect the world even if they are not present in a scene. Because they're so powerful, bosses usually attract crowds of minions that do their bidding.
veteran: Add 4 HP and 1 attack if the creature is highly experienced, like a veteran town guard, a professor of magic, or an ancient elemental.
big: Add 10 HP and 1 attack if the creature is much larger than the players, like a bear, a giant spider, or a hill giant.
colossal: Add 40 HP and 4 attack if the creature is orders of magnitude larger than the players, like a sandworm, a kraken, or a titan.
regeneration: At the beginning of each of its turns, the creature recovers half of its hit point maximum.
invisible: The creature cannot be seen with natural vision.
extra attack: The creature can attack twice during its turn instead of once.
evasive: The creature has an extraordinary method of movement. Choose one: it can fly, it can climb quickly, it can burrow and travel underground, it can teleport brief distances, or it can outrun other creatures by foot.
lifetap: When the creature damages an adversary, it recovers hit points equal to the amount of damage dealt.
horrifying: The creature is so grotesque, otherworldly, or grim that it causes immense fear in anyone who sees it. When first encountering a horrifying creature, players must roll the die. If they fail, they are frozen in fear and lose their first turn.
special ability: Give the creature a special ability belonging to one of the eight player character roles or something you invent. If the creature is a boss, like an NPC Wizard, you can give them a handful of special abilities belonging to that role. NPCs do not have adventure points, and they do not need AP to use special abilities. If you give them especially powerful abilities, use your judgment to limit how many times they can use them.
reflection: When the creature receives damage, return half of the damage received to the attacker.
invulnerable: The creature cannot lose hit points. It's probably a god.
resistance. The creature takes half damage from a type of damage, like fire or non-magic weapons.
ethereal: The creature has no physical body and cannot be affected by physical damage. (It can only be affected by magic harm.) It can freely pass through physical objects and communicate telepathically.
All spirit creatures are ethereal.
Many ethereal creatures are invisible, but not all are. Ethereal creatures that can be seen appear like ghosts: translucent creatures that glide through the air.
shapeshifter: The creature can freely change its shape to take on the likeness of other creatures. They revert to their default form upon death.
immunity. The creature takes no damage from a type of damage or cannot be affected by certain conditions, like sleep or mind control.
phase shifter: The creature can shift between physical and ethereal forms or between solid and gaseous forms.