Some people like to fully stat out every single NPC down to the last detail. Others are perfectly happy improvising everything -- they don't even know what NPCs a town might have until the PCs go there.
I'm somewhere in between. I like to give NPCs a name, and have a general idea what they are about. I don't need a full stat block but I do need a modicum of mechanical information. But I don't want to spend much time or brain power coming up with the mechanical details since I probably won't need them, and I don't want to spend too much time in prep.
So I have come up with a sort of "NPC shorthand" that I can use to describe an NPC. I find it super useful so I though I'd share.
The Number: Prowess
Question: When do an NPC's stats matter? Answer: When they are an obstacle for the PCs. (In rare instances you might see NPC-on-NPC violence but a good DM will keep this to a minimum.) So most of the time, the mechanical detail I need for an NPC is, "how much of an obstacle are they?"
Prowess represents an NPC's overall mojo, skill, power, level, abilities, everything, but mostly, it represents how difficult it is for PCs to influence, manipulate, defeat, or otherwise overcome the NPC. It works like this:
Example:
When I write down an NPC's name in my notes, I just put the prowess after their name in parenthesis, like this:
Andronsius the Alchemist (+3)
If the PCs try to persuade Andronsius to give them a discount, the DC is 13. If a PC tries to Intimidate or Bluff Andronsius, the DC is 13. If a PC is hiding and Andronsius makes a Perception check to find them, he rolls 1d20 + 3. Overall, Andronsius is not a particularly interesting obstacle and probably not super-important to the plot, or his prowess would be higher than 3.
Further Detail: Trained Skills
Sometimes, I do like to notate a little more than just a single number. The most useful thing is trained skills, which have a modifier of +prowess+5. This is only relevant if an NPC has an interesting trained skill, or is going to be a recurring character (so I need to remember between sessions what skills he has).
I tend to invent whatever skills make sense for the NPC, not necessarily sticking to those in the book. I sometimes put an ability score (often Strength) or a defense (often Will) as a trained skill, too. This can produce a great discrepancy between defenses, but that's OK; a small discrepancy isn't worth worrying about. The goal here is not to be precise or follow rigid rules, but to remind myself of what the NPC is generally capable of.
Example:
Andronsius the Alchemist (+3; Arcana, Dungeoneering, Dwarf-Lore, Will +8)
So, Andronsius is the sort of NPC who can help with questions relating to Arcana and Dungeoneering, and he knows a lot about dwarves too. He's a stubborn bugger, though, so if you try to Intimidate him, the DC is 18 instead of 13 (because he is "trained" in Will).
Further Detail: Other Stuff
Some NPCs need more than just trained skills to do their jobs. For example, the Ritual Caster feat. I just note whatever is relevant after the trained skills. This info is often independent of prowess because it doesn't factor into the NPC's role as an obstacle.
Example:
Andronsius the Alchemist (+3; Arcana, Dungeoneering, Dwarf-Lore, Will +8; Alchemist level 8, Ritual Caster level 6)
Here, Andronsius is a better Alchemist than he is a Ritual Caster. This is impossible for a PC to achieve, and level 8 is way higher than Andronsius's prowess of 3 would suggest. It's OK -- clearly Andronsius is meant to be used as a player resource for alchemical and ritual needs.
Combat Stats
These sorts of NPCs aren't usually meant as combat obstacles, so they are treated as minions and have pretty feeble stats. They have initiative and attack bonuses equal to prowess, defenses of 10+prowess, and deal damage equal to prowess. They are minions, so only have 1 HP.
The idea here is that I can calculate these stats instantly because everything is equal to prowess.
Example:
Andronsius the Alchemist
Medium natural humanoid (dwarf)
Initiative +3 / Senses Perception +3
HP 1; a missed attack never damages a minion.
AC 13; Fortitude 13, Reflex 13, Will 18
Speed 5
Improvised Weapon (standard; at-will) * Weapon
+3 vs. AC; 3 damage.
For an NPC that is meant to be "combat-capable," e.g. not a pushover, I usually note that by giving them a weapon and possibly armor. When I calculate their stats, I increase their attack and AC by 3, damage becomes 1[W]+prowess, and hit points become their attack bonus x10. Such high hit points make the NPC most like the Brute role, but that's OK. It's easy to calculate x10, and it means the NPC will stay alive long enough for interesting things to happen (alerting the town guard, etc.).
Example:
Andronsius the Alchemist (+3; Arcana, Dungeoneering, Dwarf-Lore, Will +8; Alchemist level 8, Ritual Caster level 6, warhammer 1d10)
Andronsius the Alchemist
Medium natural humanoid (dwarf)
Initiative +3 / Senses Perception +3
HP 60; Bloodied 30
AC 16; Fortitude 13, Reflex 13, Will 18
Speed 5
Warhammer (standard; at-will) * Weapon
+6 vs. AC; 1d10 + 3 damage.
More Examples
Borb the Beggar (+0)
With a prowess of +0, the PCs can basically have their way with Borb.
Frampton Dougal the Rancher (+8)
A prowess of +8 is pretty good for a human peasant, and PCs may have trouble manipulating him (forcing them to achieve their goals in other ways). However, his lack of any trained skills or other stuff means he's probably not very important to the story.
Sune Quinn the Quarter-Orc Cook (+2; Cooking, Strength, Fortitude +7; falchion 2d4)
A low prowess means that Sune isn't much of a hindrance to the PCs. But since she has a falchion it means that she is actually capable in a fight and low-level heroes should not start any trouble in the kitchen.
Kartinex, City Guardsman (+5; Streetwise +10; halberd 1d10)
This guy could help the PCs out with his Streetwise skill, but if they cause trouble he may have to hit them with his halberd.
Iarchok Silverscale, Chief Constable (+7; Intimidate, Insight, Perception, Stealth, Streetwise, Thievery +12; Bastard swords 1d10, chainmail, twin strike, dragonborn breath)
With a bunch of trained skills and powers listed, Iarchok seems like an important recurring NPC, and one who might tangle with the PCs. At this point, I would probably stat up Iarchok as a fully-fledged NPC rather than rely on the shorthand.
I'm somewhere in between. I like to give NPCs a name, and have a general idea what they are about. I don't need a full stat block but I do need a modicum of mechanical information. But I don't want to spend much time or brain power coming up with the mechanical details since I probably won't need them, and I don't want to spend too much time in prep.
So I have come up with a sort of "NPC shorthand" that I can use to describe an NPC. I find it super useful so I though I'd share.
The Number: Prowess
Question: When do an NPC's stats matter? Answer: When they are an obstacle for the PCs. (In rare instances you might see NPC-on-NPC violence but a good DM will keep this to a minimum.) So most of the time, the mechanical detail I need for an NPC is, "how much of an obstacle are they?"
Prowess represents an NPC's overall mojo, skill, power, level, abilities, everything, but mostly, it represents how difficult it is for PCs to influence, manipulate, defeat, or otherwise overcome the NPC. It works like this:
- If a PC needs to make a check to get past the NPC, the DC is 10+prowess.
- If the NPC needs to make a check, he rolls 1d20+prowess.
Example:
When I write down an NPC's name in my notes, I just put the prowess after their name in parenthesis, like this:
Andronsius the Alchemist (+3)
If the PCs try to persuade Andronsius to give them a discount, the DC is 13. If a PC tries to Intimidate or Bluff Andronsius, the DC is 13. If a PC is hiding and Andronsius makes a Perception check to find them, he rolls 1d20 + 3. Overall, Andronsius is not a particularly interesting obstacle and probably not super-important to the plot, or his prowess would be higher than 3.
Further Detail: Trained Skills
Sometimes, I do like to notate a little more than just a single number. The most useful thing is trained skills, which have a modifier of +prowess+5. This is only relevant if an NPC has an interesting trained skill, or is going to be a recurring character (so I need to remember between sessions what skills he has).
I tend to invent whatever skills make sense for the NPC, not necessarily sticking to those in the book. I sometimes put an ability score (often Strength) or a defense (often Will) as a trained skill, too. This can produce a great discrepancy between defenses, but that's OK; a small discrepancy isn't worth worrying about. The goal here is not to be precise or follow rigid rules, but to remind myself of what the NPC is generally capable of.
Example:
Andronsius the Alchemist (+3; Arcana, Dungeoneering, Dwarf-Lore, Will +8)
So, Andronsius is the sort of NPC who can help with questions relating to Arcana and Dungeoneering, and he knows a lot about dwarves too. He's a stubborn bugger, though, so if you try to Intimidate him, the DC is 18 instead of 13 (because he is "trained" in Will).
Further Detail: Other Stuff
Some NPCs need more than just trained skills to do their jobs. For example, the Ritual Caster feat. I just note whatever is relevant after the trained skills. This info is often independent of prowess because it doesn't factor into the NPC's role as an obstacle.
Example:
Andronsius the Alchemist (+3; Arcana, Dungeoneering, Dwarf-Lore, Will +8; Alchemist level 8, Ritual Caster level 6)
Here, Andronsius is a better Alchemist than he is a Ritual Caster. This is impossible for a PC to achieve, and level 8 is way higher than Andronsius's prowess of 3 would suggest. It's OK -- clearly Andronsius is meant to be used as a player resource for alchemical and ritual needs.
Combat Stats
These sorts of NPCs aren't usually meant as combat obstacles, so they are treated as minions and have pretty feeble stats. They have initiative and attack bonuses equal to prowess, defenses of 10+prowess, and deal damage equal to prowess. They are minions, so only have 1 HP.
The idea here is that I can calculate these stats instantly because everything is equal to prowess.
Example:
Andronsius the Alchemist
Medium natural humanoid (dwarf)
Initiative +3 / Senses Perception +3
HP 1; a missed attack never damages a minion.
AC 13; Fortitude 13, Reflex 13, Will 18
Speed 5

+3 vs. AC; 3 damage.
For an NPC that is meant to be "combat-capable," e.g. not a pushover, I usually note that by giving them a weapon and possibly armor. When I calculate their stats, I increase their attack and AC by 3, damage becomes 1[W]+prowess, and hit points become their attack bonus x10. Such high hit points make the NPC most like the Brute role, but that's OK. It's easy to calculate x10, and it means the NPC will stay alive long enough for interesting things to happen (alerting the town guard, etc.).
Example:
Andronsius the Alchemist (+3; Arcana, Dungeoneering, Dwarf-Lore, Will +8; Alchemist level 8, Ritual Caster level 6, warhammer 1d10)
Andronsius the Alchemist
Medium natural humanoid (dwarf)
Initiative +3 / Senses Perception +3
HP 60; Bloodied 30
AC 16; Fortitude 13, Reflex 13, Will 18
Speed 5

+6 vs. AC; 1d10 + 3 damage.
More Examples
Borb the Beggar (+0)
With a prowess of +0, the PCs can basically have their way with Borb.
Frampton Dougal the Rancher (+8)
A prowess of +8 is pretty good for a human peasant, and PCs may have trouble manipulating him (forcing them to achieve their goals in other ways). However, his lack of any trained skills or other stuff means he's probably not very important to the story.
Sune Quinn the Quarter-Orc Cook (+2; Cooking, Strength, Fortitude +7; falchion 2d4)
A low prowess means that Sune isn't much of a hindrance to the PCs. But since she has a falchion it means that she is actually capable in a fight and low-level heroes should not start any trouble in the kitchen.
Kartinex, City Guardsman (+5; Streetwise +10; halberd 1d10)
This guy could help the PCs out with his Streetwise skill, but if they cause trouble he may have to hit them with his halberd.
Iarchok Silverscale, Chief Constable (+7; Intimidate, Insight, Perception, Stealth, Streetwise, Thievery +12; Bastard swords 1d10, chainmail, twin strike, dragonborn breath)
With a bunch of trained skills and powers listed, Iarchok seems like an important recurring NPC, and one who might tangle with the PCs. At this point, I would probably stat up Iarchok as a fully-fledged NPC rather than rely on the shorthand.