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View Full Version : D&D 3.5: NPC levels (warning: math inside)

Privateer
2011-01-29, 11:03 PM
Now, I'm sure I'm not the first person who thought of this, so I'd like to hear other people's take.

I figured I'd make a little thought exercise to figure out how many NPCs should there be of what level. To do that, I calculated the chances of a 'newborn' level 1 NPC making it to a particular level.

So, let's do some math. We'll take an army, and we'll keep throwing it against an equivalent army until there is only one soldier left - the one who survived all fights and progressed to the highest level. At each iteration, any soldier will have a 1 in 2 chance of survival, since he is facing his equal and the outcome is truly random.

So, suppose we had 2 soldiers of level 1 in our army and they each fought an enemy until either our soldier or the enemy one was dead. After the dust settles, 1 of our 2 soldiers won and survived, and 1 of the enemy soldiers won and survived. How much experience did he gain?

http://www.penpaperpixel.org/tools/d20encountercalculator.htm
The calculator above says 300. In other words, a soldier would need to survive three such fights (and a bit, but I'm rounding down) in order to earn enough experience to become level 2. In fact, plugging in different levels into the calculator we will get the same result regardless of level - winning an encounter with an enemy of the same level as yourself will give you 30% of experience needed to progress to the next level. So in total you need to win 3 battles at every level to advance.

Meaning that a soldier's chances to advance a level are 1 in 8. That is, for every single level 2 NPC in your world, there are seven who died trying.

Chances to advance two levels and make it to level 3 are 1 in 64.

The general formula is: Padv(X) = 1/(8^(X-1)), where Padv(X) is the probability of any given soldier advancing from level 1 to level X.

Like any exponential, this explodes VERY quickly:

Padv(20)= 1 in 1.15*10^18 ( that is, a level 20 character would appear once in 192 MILLION Earths)

So it looks like the odds of even a single NPC surviving long enough to reach a moderately high level are miniscule.

Assumptions used:
1. All newborn NPCs start at level 1.
2. NPCs always fight enemies that are exactly their level and number.
3. Fighting encounters is the only way for NPCs to earn experience.
4. NPCs earn experience and have the same experience thresholds per level as PCs.

Number 2 is the questionable one, but seems a fair approximation. Sure, in reality fights are often unfair with one side strongly favoured, but just like an NPC would find it safer to hunt lower-level foes, so would he himself be an easy prey for those above his level.

The Pressman
2011-01-29, 11:07 PM
Assumptions used:
1. All newborn NPCs start at level 1.
2. NPCs always fight enemies that are exactly their level and number.
3. Fighting encounters is the only way for NPCs to earn experience.
4. NPCs earn experience and have the same experience thresholds per level as PCs.

Number 2 is the questionable one, but seems a fair approximation. Sure, in reality fights are often unfair with one side strongly favoured, but just like an NPC would find it safer to hunt lower-level foes, so would he himself be an easy prey for those above his level.

I assume newborn means beginning of career, so no beef there. However, it would be reasonable that, depending on class, an NPC could gain XP in some other manner than fighting. However, I may simply be seeing a different kind of NPC.

Tael
2011-01-29, 11:09 PM
Assumptions used:
1. All newborn NPCs start at level 1.
2. NPCs always fight enemies that are exactly their level and number.
3. Fighting encounters is the only way for NPCs to earn experience.
4. NPCs earn experience and have the same experience thresholds per level as PCs.

Unfortunately point 3 is also not true. Most NPCs actually reach about level 5 or so without any fighting whatsoever. There are tons of mid level merchants and nobles and casters who have never fought more than once or twice in their lives.

Privateer
2011-01-30, 03:24 AM
Unfortunately point 3 is also not true. Most NPCs actually reach about level 5 or so without any fighting whatsoever. There are tons of mid level merchants and nobles and casters who have never fought more than once or twice in their lives.

Yes, that is how many worlds are set up. But the implication is that this merchant, who only fought once or twice in his life, is as strong in combat as a level 5 soldier (if merchant's class is PC, or as 2-3 level soldier if he's NPC classed). But a level 5 soldier is someone who won 1 in 32,000 odds.

If that's the case, perhaps a merchant who never fought in his life should not be a level 5, unless he's truly extraordinary?

Anonymouswizard
2011-01-30, 08:01 AM
If that's the case, perhaps a merchant who never fought in his life should not be a level 5, unless he's truly extraordinary?

Most people would be level 1 by the time they had finished education (with higher education rewarding higher int/wis), and non-combatants would gain a level every 10 years or so (as an assumption). Now assuming they start work at an age of 20, by the time they retire they have been in work for 40 years or so, giving him about 4 extra levels. Now he is old and has taken penalties to his stats, but his experience in his career has granted him extra levels, giving him more skill points (and, as a commoner or expert, skill points would be the main benefit of leveling for common people), and another feat (most likely skill focus or other non-combat feat).

Due to the nature of different jobs, and assuming a life-span and retirement age similar to those in first world countries now, we can assume that even with each day giving a worker a fraction of a point of XP most workers would be level five by the time they retire. Due to the nature of their classes, no they would not be as good in combat as a 5th level soldier, but there is nothing to say that a farmer could not be deadly with that scythe he has been using for forty plus years.

By the way, you misspelled maths

2011-01-30, 08:55 AM
3. Fighting encounters is the only way for NPCs to earn experience.

Uh, no. No, no, no. You don't get XP for killing stuff. You NEVER got XP for killing stuff in 3.X.

In 3.X you get XP for overcoming challenges (hence why monsters have challenge ratings and don't just give a flat number of XP like they did in prior editions.)

But fighting isn't the only way to overcome a challenge. You can talk to the hobgoblins and pay them off so they either leave you alone, or if you roll well enough they might join you (for a while, at least.) You get exactly the same number of XP for that as you do for charging in and lopping their heads off.

Toliudar
2011-01-30, 09:04 AM
Meaning that a soldier's chances to advance a level are 1 in 8. That is, for every single level 2 NPC in your world, there are seven who died trying.

This is also inaccurate. Just as killing is not the only way to overcome obstacles, dying is not the only result of failure.

J.Gellert
2011-01-30, 09:28 AM
Besides what has been said, they are not only fighting level-appropriate challenges. When a band of goblins or kobolds attacks your village, you can kill low-CR creatures to your heart's content, making your levelling process similar to that of adventurers (risk-free!).

Privateer
2011-01-30, 03:32 PM
Now assuming they start work at an age of 20, by the time they retire they have been in work for 40 years or so, giving him about 4 extra levels.

Why should they? Based on what does a farmer, leading a mostly peaceful existance, get to level 5, when only 1 in 32,000+ soldiers ever gets that high by constantly facing deadly combat?

The way the system is structured, your class is irrelevant when you gain experience. So you conscript 100,000 18-year-old peasants into your army, then have it face constant battles time and time again versus ever-growing opponents, until you are left with just three heroic survivors that kicked ass every single time. I, on the other hand, have a tiny farmstead with three 60-year-old farmers that took fighter class when they were 18, and never fought since, but spent 40 years farming. Are we really saying that your three and my three are the same, barring ability decay due to age? Come on, one is the best soldier in 32,000, bloodied in many tough battles. The other is an old farmer.

Now about earning experience for non-combat, and about failure not leading to death. True, in theory, but how many times does it actually happen in your campaigns? When your party runs into bandits, how many times did the bandits actually keep their lives after losing the challenge? Not many, my guess. As for earning experience for non-fighting challenges, again, typical adventurers don't seem to get exp in this fashion in most campaigns. So even if we postulate the existance of level 5 farmers based on this, we can't justify many other adventuring groups of high level existing in the world, since their exp earning process would be fighting-based.

Furthermore, because levels primarily impact your fighting abilities, not your peaceful skills (lvl1 has skill 4, lvl2 has skill 5, but lvl2 has twice the hit points of lvl1), one could argue they should be based on fighting.

And I think I already covered the fact that you don't always fight your own level. Sure, killing goblins is easy exp, but when that dragon shows up to attack your village instead, you die immediately, so there are pluses and minuses both ways, it's just luck.

EDIT:

Actually, I shouldn't jump to conclusions, so I deleted the last paragraph. Basically, I'm trying to figure out what levels actually mean in the NPC world s.t. I could measure PC characters against their enemies. It always seemed weird to me that some DMs just scale your enemies and you end up with level 12 town guards... So, if people would like to share their views, I'd love to see it. Could you post your thoughts in the format of: NPC level range ---- typical position in society. So far I saw:

1-5 ----- most professional, depending on level of experience in their field (possibly age).

Toliudar
2011-01-30, 04:15 PM
Now about earning experience for non-combat, and about failure not leading to death. True, in theory, but how many times does it actually happen in your campaigns? When your party runs into bandits, how many times did the bandits actually keep their lives after losing the challenge? Not many, my guess. As for earning experience for non-fighting challenges, again, typical adventurers don't seem to get exp in this fashion in most campaigns. So even if we postulate the existance of level 5 farmers based on this, we can't justify many other adventuring groups of high level existing in the world, since their exp earning process would be fighting-based.

Ah! I suspect that this is coming down to a difference in play styles, then. Especially with humanoid opponents, I'd say that my RL group kills everybody less than half the time, and there's a significant chance that there's no combat at all.

If you grant the existence of story awards, roleplaying XP, etc, then it's entirely likely that there are mid-level adventurers out there who haven't left thousands of corpses in their wake. Of course the PC's advance more quickly than just about anyone else - it's their story.

By your logic, someone who trains with the army for a decade, learns four forms of martial arts and practices archery daily is not as good a shot as a bugler who lives through a dozen battles, and manages to stab someone a couple of times. Does this make any more sense than an Expert getting experience for years of honing their craft?

2011-01-30, 04:22 PM
But a level 5 soldier is someone who won 1 in 32,000 odds.

This right here is what makes E6 make so much darn sense. Yeah, a level 1 and a level 6 character are still technically doing the same thing, but the plane of experiences and challenges faced by the level six are legendary in nature, without transcending into a new state of power. (As a side note, E6 NPCs are generally very low in level (1-3 on average))

ffone
2011-01-30, 04:26 PM
Lots of good flaws pointed out here.

Another one is that the XP table is for PCs. NPCs of a given level are generally weaker (Lower ability scores, less gear, possibly NPC classes instead of PC classes.)

Which means (although there's no rule for it) they should get more XP for a given encounter than a PC would.

Privateer
2011-01-30, 04:30 PM
By your logic, someone who trains with the army for a decade, learns four forms of martial arts and practices archery daily is not as good a shot as a bugler who lives through a dozen battles, and manages to stab someone a couple of times. Does this make any more sense than an Expert getting experience for years of honing their craft?

Hmm, point. If the PCs paid money or did a quest to be allowed to train with skilled fighters/magicians, a DM should have given them exp for doing it. So it stands to reason that highly trained soldiers can get some exp without fighting (though I'd still postulate there is no substitute for real combat so they shouldn't be allowed to become level 5 without actually being veterans).

BUT. While the above is true for fighting classes, it absolutely isn't for peaceful Experts! Because levels are mostly about fighting abilities, it would be absurd for an experienced soldier of level 2 to lose to an old level 5 Expert farmer or miner.

mucat
2011-01-30, 05:08 PM
Why should they? Based on what does a farmer, leading a mostly peaceful existance, get to level 5, when only 1 in 32,000+ soldiers ever gets that high by constantly facing deadly combat?

You are arguing in circles here. You're taking that one-in-32000 figure as an established fact, and using it to defend the very set of assumptions that it flows from.

Now about earning experience for non-combat, and about failure not leading to death. True, in theory, but how many times does it actually happen in your campaigns? When your party runs into bandits, how many times did the bandits actually keep their lives after losing the challenge? Not many, my guess.
Really? We play very differently. Do the bandits in your campaign keep fighting when it's clear they're going to lose? Or do the PCs make a point of tracking down and killing every defeated opponent?

Even if the answers to those questions are "yes," do you envision that most off-screen fights between NPCs also end with the loser dead? That's a very significant assumption, and not at all the way things work in the real world. Even if a military engagement is a total rout, most people on both sides are still alive at the end. There will typically be more wounded soldiers than dead (and in a D&D world with even low-level magical healing exists, you're not going to see huge numbers dying of wound sepsis like they did in the pre-modern real world) and more routed or captured soldiers than wounded. Presumably the soldiers still gain XP for fighting and surviving the battle, even though most of them did not actually kill anyone.

Someone who has fought in several battles is considered a hardened veteran in real life, and presumably that would mean they've gained an experience level or two in your world. (Not necessarily a lot of levels. A second-level warrior could qualify as a seasoned veteran in a an army of mostly first-level combatants.) But most of the soldiers who fought in those battles would survive to gain that level, not one in eight.

As for earning experience for non-fighting challenges, again, typical adventurers don't seem to get exp in this fashion in most campaigns.

PCs do get experience for non-fighting challenges -- do PCs in your campaign never sneak past or outwit a dangerous enemy, or do they do these things but somehow not get experience for it? -- but rarely for non-adventuring challenges. This is simply because the typical campaign is about adventure; it again doesn't necessarily reflect what the NPCs are doing off-screen.

That fifth-level rogue probably didn't gain her skills by killing people; she gained them by surviving a street-rat childhood and living by her wits ever since. If she has ever killed someone, she probably regards it as a serious screw-up -- not necessarily because her conscience bothers her, though it might, but because she knows it's smart to be elsewhere when violence starts. Your one-in-32000 figure shows exactly why.

Similarly, most a fifth-level NPC wizards got that way by years of study, not by spell duels to the death. The NPC monk meditates and trains, the priest carries out his god's agenda, and the druid communes with nature. Even an NPC fighter or barbarian has probably been through a lot of sparring sessions (for the fighter) or casual brawls (for the barbarian), punctuated by an occasional "serious" fight ending in missing teeth and broken bones, and by only a few actual battles to the death.

PCs presumably could gain levels this way, but it wouldn't be the kind of game most players want. So instead they go out and risk their lives on crazy adventures...and in recompense, they do tend to gain levels much faster than NPCs. That fifth-level NPC has developed that skill over a lifetime's work, while depending on the campaign pace, a PC might match his level after a year or less of adventuring. (As Haley argued to V!)

Runestar
2011-01-30, 05:16 PM
DMG2 seems to suggest the existence of lv20 experts. How did they get that high? :smallconfused:

ffone
2011-01-30, 05:22 PM
DMG2 seems to suggest the existence of lv20 experts. How did they get that high? :smallconfused:

Obviously, each one of them killed

"adv(20)= 1 in 1.15*10^18 ( that is, a level 20 character would appear once in 192 MILLION Earths)"

...minus 1 other Experts.

You know that guild system and those labor unions. Rough bunch, the lot of 'em. You don't want to be in line of effect when the carpenters and masons start arguing over the castle blueprints, let me tell you.

mucat
2011-01-30, 05:27 PM
Actually, I shouldn't jump to conclusions, so I deleted the last paragraph. Basically, I'm trying to figure out what levels actually mean in the NPC world s.t. I could measure PC characters against their enemies. It always seemed weird to me that some DMs just scale your enemies and you end up with level 12 town guards... So, if people would like to share their views, I'd love to see it. Could you post your thoughts in the format of: NPC level range ---- typical position in society. So far I saw:

1-5 ----- most professional, depending on level of experience in their field (possibly age).

I prefer lowish-level worlds, where most adults are first through third level. A fourth-level character would be a respected (or despised) professional, and an eighth-level one would be an authority in his or her field. A twelfth-level character is probably quite famous, and a sixteenth-level one is legendary. Higher level characters than that are whispered rumors, and may or may not actually exist. If the PCs reach that level, they will be world-shaking heroes or villains...and then they will probably find that a few other characters of that level do exist after all, and don't appreciate the PCs' interference.

I also tend to assume that the main thing determining the level an NPC can rise to is some combination of talent and drive, not the passage of time. Your typical village blacksmith hits Expert level 2, maybe 3, by age of 30 or so...and just stays there. The challenges he takes on become routine, and he's just not that great a smith. The level-6 smith hasn't just been doing it longer; he also has an unusual level of talent. And the level-12 smith who invents revolutionary new techniques is a rare genius; few others would have matched his skill even if they lived for centuries.

PCs are automatically assumed to be in that elite group of potential masters, again because that makes the game fun. As long as they keep taking on challenges, PCs keep gaining skill and power, where most NPCs, even adventurer-class ones, eventually come to accept that a third-level spell is about all they're capable of. (And in itself, that places them above a lot of other, less talented wizards they know.)

Jarawara
2011-01-30, 06:28 PM
Hmm, point. If the PCs paid money or did a quest to be allowed to train with skilled fighters/magicians, a DM should have given them exp for doing it. So it stands to reason that highly trained soldiers can get some exp without fighting (though I'd still postulate there is no substitute for real combat so they shouldn't be allowed to become level 5 without actually being veterans).

BUT. While the above is true for fighting classes, it absolutely isn't for peaceful Experts! Because levels are mostly about fighting abilities, it would be absurd for an experienced soldier of level 2 to lose to an old level 5 Expert farmer or miner.

This is not an absurb scenario. Looking at real-life examples, I've seen fights break out where the old shopkeeper kicked the ass of the marine returning from the war.

Fighting is often an expression of willpower and a calmness of mind. You win the fight because you are willing to take the next step, not because you trained in Kung Fu and Karate and Karaoke. You win because you were willing to harm or kill the other guy faster they they were willing to harm or kill you.

I'd put money on the old guy who's been around rather than the young, cocky marine, regardless of those shiny decorations he wears on his chest. He may have seen 'death', but he's just not seen enough of life yet.

*~*~*~*

As for typical level assumptions, I agree that most NPC's are going to be in the level 1-5 range. But of course, I'm an E6 kind of guy. Even without the E6 ruleset for that, I've never had characters exceed 6th level in my games, after 30 years of playing. I've heard of level 20 NPC's, but those are in level-20 campaigns, which already break any assumptions of reality.

New NPC's entering the work-force will be 1st level. With some experience under their belt, they can advance to 2nd level. So can those Orcs, so beware. After that, pretty much only the 'leader' or 'named' characters will advance on to 3rd level and beyond, with most NPCs topping out around 5th level. Significant movers and shakers can exceed that, but they were going to be detailed as PC classes anyway. (You don't make a scary BBEG by giving him 3 levels of warrior, 4 of expert, and a level dip into aristocrat for flavor!)

Privateer
2011-01-30, 08:09 PM
Thanks for the level guidelines; they're basically in line with my views.

Commoners and experts are 1-3, maybe up to 5.
Anybody 5 and above is already a hero, probably in charge of something.
Anybody above 7 or 8 is most likely in charge of something very big.
Anybody 10 and above is a unique genius, a national treasure, maybe the king himself, or a great wizard.
Anybody 12+ is very few and far between. Getting there puts you in a totally different class.

But I thought this was not quite the accepted norm. Because some things follow from such assumptions. For example, many magical items have very high level requirements. In a world where there are very few 12+ characters, such items should be extremely expensive or unobtainable. And in books like Forgotten Realms, stats for the kings of nations are given and they are pretty high indeed.

sfweb
2011-02-07, 02:09 AM
I am also agree with you.

Unfortunately point 3 is also not true. Most NPCs actually reach about level 5 or so without any fighting whatsoever. There are tons of mid level merchants and nobles and casters who have never fought more than once or twice in their lives.

faceroll
2011-02-07, 06:31 AM
This is also inaccurate. Just as killing is not the only way to overcome obstacles, dying is not the only result of failure.

Exactly.
What are casualty rates typically in medieval warfare? 10% to 30%?

Thanks for the level guidelines; they're basically in line with my views.

Commoners and experts are 1-3, maybe up to 5.
Anybody 5 and above is already a hero, probably in charge of something.
Anybody above 7 or 8 is most likely in charge of something very big.
Anybody 10 and above is a unique genius, a national treasure, maybe the king himself, or a great wizard.
Anybody 12+ is very few and far between. Getting there puts you in a totally different class.

But I thought this was not quite the accepted norm. Because some things follow from such assumptions. For example, many magical items have very high level requirements. In a world where there are very few 12+ characters, such items should be extremely expensive or unobtainable. And in books like Forgotten Realms, stats for the kings of nations are given and they are pretty high indeed.

Not a fan of that break down.
I like level 7-12 to "be in charge of something big"
17+ are the really big badasses that go down in the history books.

A level 20 fighter isn't as special as a level 15 wizard, because a wizard has a quadratic power progression, where his ability to alter the world changes dramatically with each level.

Coidzor
2011-02-07, 06:48 AM
Assumptions used:
1. All newborn NPCs start at level 1.
2. NPCs always fight enemies that are exactly their level and number.
3. Fighting encounters is the only way for NPCs to earn experience.
4. NPCs earn experience and have the same experience thresholds per level as PCs.

Assumption 5. Killing one's opponent is the only way to get experience from fighting and defeating them.

A subset of that is that training is nonexistent or irrelevant such that sparring is an impossibility of being of any use whatsoever.

Avaris
2011-02-07, 08:06 AM
Don't know if you'll have seen this before, as its been around for a while, but if you're looking at making NPC levels logical you might be interested in this article (http://www.thealexandrian.net/creations/misc/d&d-calibrating.html). It sets the bar even lower than you do; according to the article, Aragorn could be stated as level 5.

Tyndmyr
2011-02-07, 08:07 AM
Yes, that is how many worlds are set up. But the implication is that this merchant, who only fought once or twice in his life, is as strong in combat as a level 5 soldier (if merchant's class is PC, or as 2-3 level soldier if he's NPC classed). But a level 5 soldier is someone who won 1 in 32,000 odds.

If that's the case, perhaps a merchant who never fought in his life should not be a level 5, unless he's truly extraordinary?

Expert isn't as good at combat as warrior. Lets assume that NPCs are in fact NPC classed normally, and that they take classes with at least some relationship to their profession.

After all, a straight warrior isn't going to be very good at being a merchant compared to an expert.

That article is over-quoted. It ignores details like the fact that a Balor IS a Balrog in the same way that halflings are hobbits. Encumberance? Cmon, encumberance is a terrible method of simulating reality. Increasing strength linearly does not exponentially increase carrying capacity. It also doesn't account for Gandalf, at all. There's absolutely no way that Gandalf is level 5 or less. The fact that Aragorn cannot treat Frodo's wound doesn't mean jack, since it's basically an effect that in D&D is a magical disease, not a mere loss of hp. The fact that a ranger can't fix that is...normal.

Jarawara
2011-02-07, 10:26 AM
Don't know if you'll have seen this before, as its been around for a while, but if you're looking at making NPC levels logical you might be interested in this article (http://www.thealexandrian.net/creations/misc/d&d-calibrating.html). It sets the bar even lower than you do; according to the article, Aragorn could be stated as level 5.

+1 to this.

Though I would be willing to go as high as 8th level for Aragorn, just because that would put him ahead of all of the PC's of my gameworld. Some heroes of legend should *remain* heroes of legend, and not just become the lightweight sidekick to the PC's.

As for Gandalf... he's a 5th level Wizard. But he's also a fighter, might have some druidic spells, maybe a little bit of sneakiness to him, and oh yeah, he's a freaking outsider, perhaps upward of being a demigod. But just accounting for his spellcasting abilities, yeah, he can be modeled at nothing higher than 5th level.

Tyndmyr
2011-02-07, 10:57 AM
As for Gandalf... he's a 5th level Wizard. But he's also a fighter, might have some druidic spells, maybe a little bit of sneakiness to him, and oh yeah, he's a freaking outsider, perhaps upward of being a demigod. But just accounting for his spellcasting abilities, yeah, he can be modeled at nothing higher than 5th level.

Negative. Leaving aside that he clearly has gish abilities and casts lightening bolt(as gandalf the grey), he also had the magical firepower to, after breaking the bridge(stone shape?), solo a balrog. After taking a crapton of fall damage by free falling into an abyss. Feather fall cannot have been used, since he was entangled with the balrog's whip. He then fought for two days continually, died, and came back from the dead.

I would be interested in hearing how these abilities can be reasonable represented in five levels.

SirNMN
2017-04-29, 10:47 AM
Me too I would guess that he is a mystic theurge but might be something more

Darth Ultron
2017-04-29, 12:40 PM
Commoners and experts are 1-3, maybe up to 5.
Anybody 5 and above is already a hero, probably in charge of something.
Anybody above 7 or 8 is most likely in charge of something very big.
Anybody 10 and above is a unique genius, a national treasure, maybe the king himself, or a great wizard.
Anybody 12+ is very few and far between. Getting there puts you in a totally different class.

I spread this out a little more.

1-5 are just about all young newbbes, with some folks that just don't care and never really applied themselves.

6-11 are experts, professionals and people that have worked hard.

12-is the Hero bench mark.

13+ are famous and infamous.

Knaight
2017-04-29, 02:05 PM
Assumptions used:
1. All newborn NPCs start at level 1.
2. NPCs always fight enemies that are exactly their level and number.
3. Fighting encounters is the only way for NPCs to earn experience.
4. NPCs earn experience and have the same experience thresholds per level as PCs.

Number 2 is the questionable one, but seems a fair approximation. Sure, in reality fights are often unfair with one side strongly favoured, but just like an NPC would find it safer to hunt lower-level foes, so would he himself be an easy prey for those above his level.

5. Everyone fights to the death.

It's not stated in these four, but it's important - a 50% death rate for a losing army is very high, a 50% death rate overall is the sort of thing that makes a battle stand out throughout millennia of military history. That makes your 1/(2^3) value change, where the 2 gets reduced somewhat and is somewhere between the 1 and 2 range. Assumption 2 is also pretty terrible - if only 1/8 of the people make it to any given level than even hitting level 2 means that you've got an advantage against almost everyone you fight. That makes analysis a fair bit harder (though Markov chains should be able to do it), but it's necessary for the model to be useful at all.

Telok
2017-04-29, 02:37 PM
Personally, for my own world building, I use this.

Race Max Age Level Age Event bonus Per event
Human 100 10 1 level for active role in major event 1
Dwarf 375 30 1 level for participating in two major events 0.5
Elf 600 60 1 level for surviving four major events 0.25
Gnome 375 30 1 level for active role in two minor events 0.5
Half-elf 175 15 1 level for participating in four minor events 0.25
Half-orc 75 10 1 level for surviving eight minor events 0.125
Halfling 160 15

Major Events: Major wars, historical turning points, epic journeys, major exploratory expeditions
Minor Events: Local conflicts, important trade negotiations, very large battles, powerful discoveries or inventions

Napoleon, age 23, Aristocrat 1/Warrior 1.
+.25, the Revolution in 1789 2.25
+.5, the siege of Toulon & the Battle of Saorgio (1793 -94) 2.75
+.25, assorted minor events (1794 -95) 3
+.5, the defeat of the royalist insurrection (1795) 3.5
+1, age level 4.5
+1.75, First Italian campaign (1797) 6.25
+1.5, the Egyptian expedition (1798 -99) 7.75
+1.25, coup d'etat, ruler of France (1799) 9
+1.5, assorted politics and wars through 1803 10.5

Of course that doesn't stop at the end of his career. I figure he probably got about 3 to 5 more levels after that.

But that's just what I use.