What problems could E6 introduce when used for Dungeons and Dragons Fifth edition?

Question

Recently I started to think about running a campaign in low fantasy setting, where magic is limited both in number and scope of power. Some time passed and I still think about that idea, so (at least if I am not mistaken) it was not a temporary "oh, that's cool" moment, but an idea for a campaign I would not want to go to waste. The problem started when I wanted to pick an appropriate system for that from those I knew fairly well.

Considering the campaign theme: it was about a group of monster hunters going against what was considered by normal society "monstrous and impossible to beat", as well as having magic in limited form, as well as greatly reduced influence from eldritch beings or otherwordly phenomena.

On the problem

Many of the systems I played just don't cut it:

• Shadow of the Demon Lord is literally centered around an eldritch being and otherwordly phenomenon (demon lord and his shadow), which is quite visible in mechanics of the system. Not to mention magic in this system is unreal, some spells going on the plot-ending scale. Sooo, no.
• Cthulhu 7e is similar. Also, it is made around the "detective" part of the mythos and unraveling clues, not fighting. Which in a fight heavy campaign is the opposite of what you want. I do not want my players to make new characters every third session, or deal with mentally broken ones every second one.
• Fragnarok is a system for one-shots, not campaigns.
• Neuroshima 1.5 is a system built into the specific, futuristic world, and the world is a part of neuroshima 1.5 ruleset, which in an entirely homebrewed world is a problem. And there are many problems with the system I personally do not like, so no.

Which left me without really other choices but to go to my first, and most familiar system - D&D 5e. But before, you know, an actual question I came here with, the helping question: is there a system, that could work for this idea? I believe Warhammer whatever edition won't cut it - I know nothing of those systems, I never played one, and they seem complicated enough to not wanting to pick them up and work them into what I think I want. I have heard about Witcher RPG, but cannot say if it would be good for such an idea. If you know a relatively quick to learn system, that would fit right in, I would be glad for you pointing me in the right direction. If not, just skip this whole part, and thanks for reading anyway.

The actual problem

Theoretically, the best I would feel when running in D&D 5e. But the problems were quite obvious. Dungeons and Dragons is in no way or form low-fantasy from the mechanical perspective. Some high level spells or abilities are beyond whatever can be sanely called "low fantasy". The world can be made to reflect what I want of it, the problem is with players and their options. But knowing how popular this system is, I knew for a fact someone somewhere had similar problem. So I started digging.

Skimming through the internet I came across something called E6, a variant rule for Pathfinder 1e and D&D 3.5e. I know 5e very well, and I am aware those systems are closely tied, so I thought about running the campaign in 5e D&D with E6. But as much as I know 5e, I do not know much about 3.5, nor Pathfinder 1e or 2e. So my question is: What problems would appear in applying this rule to the 5e system, if any? Would there be problems with the way feats are being treated in 5e in contrast to 3.5e? Maybe something with progression after that 6th level? I can see some, but I'm most afraid I just miss on something big, and problems will start piling up after the start of the campaign, making it a nightmare midway.

Answer 1

Standard E6 is fundamentally D&D 3.5 capped at level 6, with further progression by feats only. This resolves a lot of mechanical problems specific to D&D 3.5 at higher level: combat becomes slow due to options and hit points, arcane casters became overpowered due to the quadratic wizard effect, excessive focus on character build and prestige classing as a source of power, high level characters become invincible, reasonable challenges for specialized characters become impossible to non-specialized characters due to the unbounded numbers, etc.

D&D 5e already solves most of those mechanical issues, making E6 less relevant. You also have the problem that feats are less common and more powerful in 5e, so they're not as useful as a means of progression and character customization. In 3.5, feats made your character unique, and there were hundreds of feats in sourcebooks. In 5e, I could forsee the entire party taking Tough and all the casters taking armor proficiency, resulting in everyone being the same.

However, it sounds like what you're interested in is the thematic element of E6, which is a world where human characters above level 6 do not exist, so the player characters are exceptional even at low level. Now you have a world where, say, CR 10 monsters still exist, but there are no NPCs of high enough level to trivially defend the town from one and overshadow the player characters' ability. You can do that pretty easily with the standard 5e rules.

The challenges I forsee when attempting the E6 approach in 5e:

• It's hard to bring more resources to a single fight. The limit of one concentration spell per caster means each caster can generally only have one buff spell or summon spell active at a time, and summon spells are not common. There's no Leadership feat to allow you to bring a cohort or allies to a fight.
• Magic item crafting isn't a standard rule in 5e. You can't craft custom magic items as you might in 3.5. The item attunement cap limits the amount of power you can gain from item loadout.
• "Solo" monsters are more powerful in 5e, often having legendary actions and other things to make them more powerful against a party.
• Feats, as I mentioned, are less useful as a post-level-6 method of advancement. Aside from taking ability scores up toward 20, feats in 5e do not generally increment numbers the way 3.5 feats might. There's nothing like Weapon Focus or Weapon Specialization.

In short, 5e is balanced so that you don't need an E6 approach, but that balance also inhibits the ability of an E6 approach to take on monsters who are powerful. D&D 5e is not geared so well for a level 6 party taking on level 10 solo-type monsters.

A previous low-powered campaign world of mine handled it thusly: NPCs above a certain level are largely unheard of, but when the PCs reached the level cap, they were nonetheless able to perform quests to seek out sources of power allowing them to reach even higher level; e.g. invent 4th level arcane magic, perform a service to gain a boon from their deity allowing 4th level magic, etc. Mechanically it was very similar to standard D&D, but thematically it recontextualized the party in a campaign world where they might be the most powerful individuals in the world by level 10, without having to run the campaign until level 20 to achieve that. Fighting a CR 10 dragon as a level 10 party is still legendary when nearly everyone in the world is level 1 and even the king is level 5 and only owns two magic items.

Answer 2

Frame Challenge - This is a worldbuilding problem

From seeing your comments and the 'Actual Problem' statements, it sounds like the problem you have is a worldbuilding problem, not a game mechanics problem. And since this is a worldbuilding problem, you don't need to alter player-facing game mechanics in order to fix it. You can solve it with worldbuilding.

Basic Premise: Player Characters are Truly Exceptional

If your problem is that you want these threats to seem insurmountable to the common people, then all you have to do is turn down the power curve for common people. Why are there no archmages around, why are there no max-level Clerics, why are there no Fighters who can turn the course of a war on their own? Simple: same reason our world isn't jam-packed full of Albert Einsteins.

The kind of talent necessary to achieve such heights is so rare in your setting as to be practically non-existent. For player characters, it's just assumed that as long as they earn enough Experience Points, anyone can reach 20th level. But your worldbuilding doesn't have to make that true for everyone. Certainly not for NPCs.

Real people have limits, they have upper thresholds of what they are capable of. It doesn't matter how hard I work, I'll never be a World's Strongest Man contender, I don't have the build for it. It doesn't matter how hard I study, I'll never be on the level of Stephen Hawking. So, you just slide down the upper limits of what a 'normal person' is capable of to wherever you'd like it. And then keep in mind that your Player Characters are not normal people.

Sure, maybe some grand library has preserved spellbooks of some ancient genius wizard and they have heard of grand and powerful spells that can reshape reality or smite entire armies. But nobody alive can actually cast them. There are legends of savage warriors whose fury can sustain them beyond death, of tricksters and thieves capable of feats beyond reckoning, of heroic champions who have held the line against innumerable foes.

But that's the stuff of legends. There's nobody like that alive today (until the PCs carve their own legend, of course).

Extant Example: Eberron

The Eberron setting is precisely an example of this. Its creator, Keith Baker, describes Eberron as a "Wide Magic, not High Magic" setting. Now, that's not to say that your 'low magic' setting needs to adopt the 'wide magic' of Eberron...it's simply an example to show you that you can create a setting where the heights of power are not available to anyone except the Player Characters.

In Eberron, your typical soldier who is a veteran of The Last War is...like...maybe 2nd or 3rd level? And, in the 3.5E version of Eberron...they weren't even a Fighter. They were a Warrior, which is a nerfed NPC-only knockoff of a Fighter. A 5th Edition comparison would be basically the equivalent of the Sidekick Classes presented in Tasha's.

Your average city ruler isn't some Archmage or Martial Champion...they're a politician who could maybe hold their own in a courtly duel. The mayor of Sharn isn't going to be able to beat a PC in a fight.

Unlike in The Forgotten Realms where there are super-powerful 'heroic' NPCs all over the place; there are only 2 officially placed 'good' characters in The Five Nations that are capable of 9th level spells. And neither of them are particularly able to intervene in the world at large. Oalian the Greatpine is an Archdruid. But he's an awakened tree and doesn't move around a lot. Jaela Daran, the 'Keeper of the Flame,' is the spiritual leader of the Church of the Silver Flame and is an 18th level Cleric....as long as she's inside Flamekeep. If she leaves the building, she's only level 3.

Eberron is like this without having to change the game system. It's all worldbuilding.

Why is Eberron this way?

Well, I'll just let Keith Baker say it for himself...

From the beginning, a central idea of Eberron was that player characters are remarkable. They’re the heroes of the movie, the protagonists of the novel… and especially in pulp adventures, such heroes are larger than life. Even at low levels, player characters are more capable than most people in the world. Just consider the Five Nations: we say that magic of 3rd level is part of everyday life, magic of 4-5th level is rare and remarkable, and magic of 6th level or above is legendary. So what does that mean for the 11th level wizard, who can cast 6th level spells?
[...]
Eberron was designed with the idea that adventurers would be the greatest heroes of the age

In a second comparison...

A comparison here would be The Hobbit. When Smaug comes to Laketown, the Master of Laketown isn’t a mighty champion who can fight him. All the soldiers of Laketown are helpless against the dragon. Their only chance lies with a hero who can beat the odds and do the impossible. And in Eberron, that’s you.
[...]
These things don’t happen every day, which is why the civilization of the Five Nations still exists. But they could happen any day, and that’s why the world needs heroes. Most of the time, Laketown is perfectly stable and safe… but when the dragon shows up, the common people need a champion. As a player character you are supposed to be remarkable, because there ARE powerful malevolent forces and you may be the only ones who can deal with them.

And that sounds a lot like what you're going for. Unlike The Realms where powerful heroes are a dime a dozen, and you're the newcomers on a vast stage of heroic powers...it sounds like your world is a lot like Eberron in that way. It needs the PCs because heroes on the level of the PCs don't exist.

And you don't need to import E6 or cap player progression to do this. All you need to do is curve down the power level of friendly forces.

Answer 3

Consider Runequest

You write:

a group of monster hunters going against what was considered by normal society "monstrous and impossible to beat", as well as having magic in limited form, as well as greatly reduced influence from eldritch beings or otherwordly phenomena

and you mention that you already have experience with Call of Cthulhu. Ruenquest uses the same Basic Roleplaying framework, and replaces all the Cthulhu-specific drawbacks like sanity and modern-time investigation outlook with more appropriate fantasy trappings, equipment, magic and monsters. You get pre-made stats for all kinds of common monster types, armor, medieval weapons, etc. You do not really have to learn a new system from scratch, as the fundamental mechanics are similar to Call of Cthulhu, so this should address your concern about:

I know nothing of those systems, I never played one, and they seem complicated enough to not pick them up

In Runequest (at least in the older editions I remember), monsters like Giants or Dragons are a near-certain death encounter. Magic in general is much weaker and less flashy. And characters do not level, so the range of power is even more narrow than in bounded accuracy d20.

Runequest is often conflated with Glorantha as a setting, but you do not need to use it, you can also play a more classic pulp fantasy campaign with it.

Answer 4

Play 5e without magic

Fighters, barbarians and rogues only (without the spellcasting options). Or, for a little bit of magic, paladins, rangers, monks.

Healing potions can be herbal rather than magic.

D&D 5e makes no presumption about party composition and is “balanced” without reliance on “burst” effects; that is, encounter balance assumes no one uses single or limited use options - martial character simply attack and magic characters use cantrips.

E6 does not do what you want

The purpose of E6 is to limit 3.5e to 6th level abilities on the basis that higher level characters were overpowered. It does not limit or reduce magic as a whole, it just limits what level of power magic has.

For example, wizards can fly but they can’t teleport. Clerics can cure but they can’t raise the dead.

Answer 5

Be conservative with levels and require experience to be earned

Our OSR Coup de Greyhawk campaign has two branches with an average of hundred sessions both. The highest level is five, with a small number of characters at level four. https://www.arkenstonepublishing.net/isabout/2022/03/29/new-on-desk-116-campaign-review-time/#2-the-high-score-table

The campaign is certainly not low magic by any reasonable measure (as we see a spell or three cast during most sessions), though it is much lower magic than the extravagant modern D&D.

Some principles we use that I have also used with modern D&D (both Pathfinder 1 and D&D 5), and work fine there, too:

1. Almost everyone in the world is first level. The city watch, the farmer, the mayor, the pickpocket, the mage in the woods, even the king, all are first level unless otherwise specified. You do not get continual lights lighting up cities, or priests casting resurrections, or archmages teleporting around and fireballing anyone who earns their displeasure.
2. Characters can be competent even at first level. The class abilities only define easy adventurer solutions, but most characters are not adventurers and do not use those solutions. Someone can be an expert craftsman or a master thief while first level, but that comes with years and years of practice. Adventuring and levels are a dramatic (as opposed to realistic) way to become skilled and powerful.
3. Experience is earned, not given. We use treasure experience and quest experience, plus some minor additions, but in a monster-hunting game you would want to give experience for killing monsters. Maybe 100 experience per hit die squared, but only for those monsters that are the quest objective. Dracula in the castle, but not the wolves one might meet on the way there.
4. Traditional experience requirements. Second level is about 2000 experience, and every level thereafter doubles the requirement. Since we do not scale the experience rewards artificially, it becomes increasingly hard to earn the higher levels. This does not give a hard cap, but does provide a powerful soft cap in level.
5. Characters can die. The referee is impartial once an adventure has been started, not adjusting things to party level, or to save or to kill characters. This means that characters do die, even the cherished and high level ones. Players tend to have several characters in their stable and alternate which one they play in any particular session.

The consequence is that most characters are of first or second level, even in a long-running campaign, and feel quite mortal. The rare medium level character (about level 3+) is an asset. But even second level characters already feel competent and heroic, since the world is first level. An ogre is a terrible threat, capable of killing anyone (aside from some of those medium level characters) with a single blow, as it should be; killing serious monsters is a formidable task and challenge, not something routine that is done all the time.

This will keep the power level limited without messing with any rules besides those for experience (needed and earned). This carries the benefit of rules familiarity and easy transferability of characters from other campaigns. Since almost everyone is first level, there is an actual reason why people do not solve their own problems and need someone stupid enough to die trying to hunt those monsters.

Answer 6

A power analysis of 3e vs 5e may be of use to you.

In 3e, the ECL scale was exponential. Every 2 levels doubles the number of creatures. In 5e, doubling the number of creatures doubles the ECL (this includes the effect of encounter size scaling, with reasonable error bars).

If we treat an encounter with X creatures of CR Y as linear in X, this means that characters in 3e have expected exponential power growth, while characters in 5e have expected linear power growth.

Now, the game's ability to deliver on this is imperfect, but it is not that far off, and it does reflect the difference between the systems.

(For example, level 1 to 2 in 5e doesn't double power, it increases it by about 1/3 to 1/2; the growth curve is more like 1.25, 2, 2.75, 3.5, 5, 6 instead of 1 2 3 4 5 6; a small tweak off linear. And multiclassing/charop/magic items/etc can make 5e power growth be faster than 'random' PCs.)

Now, a level 1 PC in 3e and 5e are not that far off, fictional-power-level wise. Reaching Level 6 in 3e is +5 levels, or 2.5 doublings, or 5.65x the power level. This is roughly equivalent to level 7.

In 3e, reaching level 8 makes the PCs as powerful as 11 level 1 PCs; that doesn't happen until roughly level 14 in 5e. By level 20 the 3e encounter building guidelines say a PC is 724x as powerful as a level 1 PC; in 5e it is closer to 17x.

In short, the "snowball" effect of 3e, where PCs become one-person armies, doesn't happen in 5e (especially if you avoid lots of magic items and magic item shops) to nearly the same extent.

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If you want low fantasy, the biggest issue I suspect you'll have is the set of supernatural effects PCs have.

With L 2 spells, PCs can become invisible magically (pass without trace, invisibility) and teleport through a crack (misty step).

With L 3 spells, PCs can fly and blow up dozens of foes with fireballs, and bring back the recently dead.

With L 4 spells, PCs can turn into giant beasts, banish demons, and teleport medium distances.

With L 5 spells, PCs can mind control (dominate and geas), disguise an army as children, or blow up peoples minds, raise the dead, and distance starts to collapse (teleportation circle)

With L 6 and above spells things get even more gonzo.

A fighter at level 20 is just a deadlier level 6 fighter, capable of defeating 3 times as many foes at once. A wizard at level 20 can create new living beings and own a pocket dimension.

So one fair option is to limit PCs to 6 levels in any one class. This will avoid reaching higher level abilities. This will require a patch for Extra Attack (as 5/5/5/5 and 6/6/6/2 of all-martial classes are legitimate things to want to work).

This cuts off level 4+ spells (but not spell slots), and could keep you in the realm of relatively low fantasy for a while.