Worlds of Design: How Long Should Your Rulebook Be?

The nature of tabletop role-playing games is that the players can try to do anything, so it's impossible to cover every possibility in the rules. In a way your rules are like the programming of a video game, because you can’t cover every possibility.


Picture courtesy of Pixabay.

Among the online audiovisual game design courses I offer (on is about six hours on rules writing for tabletop games. The following discussion is specifically about the special aspects of RPG rules writing.

Tabletop vs. Video Game RPG Design​

The nature of tabletop RPGs is that the players can try to do anything, so it's impossible to cover every possibility in the rules. That's the reason why you have a human game master (GM). In video game RPGs, without a human GM, the players are far more limited in what they can do, but that’s no different than other video or board games. In a way, your rules are like the programming of a video game, because you can’t cover every possibility. So how much DO you cover?

The question really amounts to: how long do you want your rules to be? Hundreds of thousands of words as in Fifth Edition Dungeons & Dragons, or as in a Pathfinder rulebook (a massive 566 large-format pages)? Or do you want to stick to a “mere” 100,000 words, which is on the long end of the average novel length? I recently saw a game by Robin Laws quoted at 700,000 words!

Contrast this with board and card games which have rules as little as 1,000 words, where 20,000 is a lot (that’s more than the rules and commentaries of my epic game Britannia). The British 20th century composer Sir William Walton wrote only one opera; when he finished he said “don’t write an opera, too many notes”. From a design standpoint I have the same view about role-playing game rules: “too many words.”

You have to choose your emphasis, even if you write 700,000 words. What are the main attractions or foci of your game? Is it combat, interpersonal relationships, role-playing, exploration, politics, or something else? Write your more detailed rules to cover those possibilities. Don't try to be exhaustive, because if you do you'll become exhausted, and so will many of your readers. Some of them will be happy to read every word you want to write, but that's the exception. I hearken to these maxims even in role-playing games, certainly in board and card games:
  • everything should be made as simple as possible but not simpler” (Albert Einstein)
  • a designer knows he has achieved perfection not when there is nothing left to add but when there is nothing left to take away” (Antoine de Saint-Exupery).

Rules vs. Settings vs. Adventures​

Keep in mind the distinction between rules, settings, and adventures. A game must have rules, but a role-playing game does not need an explicit setting, and does not need to include adventures. The rules describe the mechanisms of the game. Rules govern what the characters can and cannot do, and how they try to do them, and the GM takes care of the rest.

Settings, on the other hand, describe the area where the player characters operate. It may be an entire world, it may be part of the world, it may be quite small or quite large. Its geography, chronology, history, technology, culture ecology, and other aspects are all part of the setting. So you can have setting books that are larger than the average novel.

Most RPGs have a default setting that determines things like: Are there rayguns? Are there horses? Are there large warships? Is there gunpowder? and so forth. For D&D the answer was "late medieval with magic added, and a little Tolkien".

Adventures describe a situation with an objective, where characters have the opportunity to succeed or fail. There can be a story imposed by the designer, or the designer can present an interesting situation and let the players write their own stories, or somewhere in between.

You are obliged to write the rules if you're going to make a game. As the game designer you're not obliged to write the setting or adventures, but either one (and especially some kinds of adventures) might make it easier for your game to function immediately when someone buys it.

Keep in mind also that role-playing games derive from miniatures games, not from board or card games. People expect board/card game rules to be precise and all-encompassing, although it often doesn't work out that way. People expect miniatures rules to require a certain amount of negotiation! In RPGs we have the GM to arbitrate and mostly avoid negotiation. Your RPG rules are most unlikely to be as precise, and certainly not as all-encompassing, as board or card game rules, because RPGs inherently involve fewer constraints. There's just a lot more you have to talk about in an RPG, unless you leave a great deal to the GM.

Game Master Rules​

That brings up a major question in writing RPG rules. In board and card game rules you have no impartial arbiter to interpret and flesh out the rules. Players will be reading the rules, and players tend to read rules the way most benefits them in the specific instance. (Of course, RPG players do this as well.) The question is, how much do you want to leave rulings to the GM?

In the early evolution of the hobby the GM was god-like in his or her effect on the game. This has changed because it's hard to be a GM, to be able to make rulings that make sense and hang together, to deal with the diverse agendas of the players. So over time games have tended to make the GM an arbiter of the rules rather than a godlike influence, with the idea that this is easier for a GM to do. The unstated objective, I think, is to enable more people to GM successfully. But it means the rules must have more and more detail, and must be more and more precise to avoid interminable arguments between GM and players. So your choice of rules length is likely to make a big difference in what kind of GM you require.

RPG and board game rules are different because there are different objectives, but mainly because games need either precise rules, or a GM. Always keep in mind, the more you try to do with a set of rules, the more likely you are to leave them unfinished!

Your Turn: Have you ever written a set of RPG rules? Did you finish? If not, why not?
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Lewis Pulsipher

Lewis Pulsipher

Dragon, White Dwarf, Fiend Folio


I've tried writing numerous rulebooks. My first I wrote when I was in Middle School and distributed to kids in my neighborhood and tried to sell it at the FLGS. Later I tried to streamline Pathfinder 1, create an "OSR clone" of 4e (before the movement really took off). Lately I've been working on a DM-less boardgame version of a B/X feeling dungeon crawler.
I end up quitting the projects because they are big for a single amateur designer, and adventure content is more likely to see use at my table.


Well, that was fun
Staff member
Heh. I've done both! My Awfully Cheerful Engine is a small booklet of 30 comic-book-sized pages with lots of colourful art, a single author (me). Simply 6 was a similar size. Level Up, which I'm publishing next year, is going to be more akin to the D&D/Pathfinder rules in size and has many writers. Judge Dredd was half the size of Pathfinder and half of that book was setting material. My three WOIN core rulebooks were about 200 pages each (you only need one of them).

So, it varies, I guess?


Rotten DM
Your Turn: Have you ever written a set of RPG rules? Did you finish? If not, why not?
Do house rules count.? My house rules are 0. Monsters want to win too. 1. Monsters cheat. 2. Follow AL rules.


Solitary Role Playing
I've dabbled with trying to write a RPG as soon as I got my first desktop computer. There are a lot of decision points, even for a light rulebook. It needs to be play tested, etc. I did that for a non-collectable card game I created in the 90s. It's very time consuming.

At the end of the day, although I enjoy the mental exercise, I'm just not willing to spend the time it takes to create a professional rpg rulebook. I prefer creating bi-weekly adventures on graph paper and GMing them for my friends.

It's my hobby not my job. ;)

I started an D20 style WW2 rpg that focused on the squad level with each character filling a specific role (rifleman, machine gunner, etc) but I didnt get far. I had the covering rules roughly thought out. The more I wrote the more complicated it became.

It’s interesting that the most popular RPG in the world is more complicated than 98 per cent of boardgames. Some suggestions why:

  • D&D has it origins in tabletop wargames, which are complex by the standards of most hobby boardgames. On top of that, it addressed the variety of different situations an RPG can present outside of combat with more rules and systems.

  • When a rationalization of the rules was carried out for 3E, the enormously popular Magic the Gathering was a major influence, a game that not only rewards system mastery and optimization, but is a hobby unto itself. It was designed to be a game with a wealth of mechanical grit and options to engage with away from the table.

  • Moreso than most games, just reading D&D books and talking about mechanics and optimization online can be a hobby. RPGs are fundamentally different from boardgames in that the players, and especially the DM, often spend hours away from the table thinking about and playing with the game. Publishers recognize this is a significant part of the market for their books.

Having said that, I think the complexity of D&D is largely down to legacy at this point. The preference of the vast majority of tabletop gamers today is for games that can be picked up and learned easily, without taking any books home. If a publisher were to poll the market for D&D today - all of the people actively playing or interested in playing - to find out their wants and preferences, without any deference to legacy or online hardcore culture, I‘m certain they would design a game that’s far less complex than what we have. And if they actually employed instructional designers and technical writers to write the thing, I expect the rules would come in at under 30 pages, including illustrations and examples.
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I've made various attempts over the years. The only one that actually came to completion was a massive overhaul of 2nd Edition AD&D... which promptly disappeared, never to be seen again. What I wanted from the game had significantly shifted between the start and the end of the project, rendering my 'perfect' set of house rules useless.

You might think I would have learnt my lesson from that, but no. Every few years I start on something new, and a few weeks later it just stops.

When people say things like "it's impossible to cover every possibility in the rules," they're often enforcing a false dichotomy and then showing how one limb of that dichotomy is implausible. To whit, it boils down to the following syllogism:
Either every possible situation must have a discrete rule, or there must be expected situations where there are no rules whatsoever.
It is impossible to make a discrete rule for every possible situation, because there are infinitely many possible situations and the rules must be finite in length.
Therefore, there must be expected situations where there are no rules whatsoever.

The problem, of course, is that the dichotomy premise is false. There is at least one other way to design rules: not as singular discrete cases, but as extensible frameworks that can be adapted to many similar situations as needed. Such frameworks DO still need human judgment in order to BE extended thus, but this does not suddenly mean the rules are completely absent on that subject. It means the rules are able to abstract relevant inputs from and furnish useful outputs to varied situations, with one rule covering many situations.

4e's Page 42 and skill challenges are examples, as are 13th Age's Backgrounds and OUTs, Fate's Aspects, and PbtA's dungeon master moves. It is entirely possible to construct extremely useful, well-designed rules that, while they might still have the occasional exception, are almost always applicable and effective for the spectrum of things players generally wish to do.

4e, to pick the example I know best, is only "rules-heavy" if you think you need to memorize every single power, feat, item, etc. You don't. You only need the things you actually use (and combing through them for optimization is either unnecessary, or easily outsourced to friendly and supportive forum-goers/drawn from already-written guides). Combat has precise rules to help cultivate pitched set-piece battles. Nearly everything else either doesn't really need rules, or is perfectly well-handled by Page 42 and SCs (though I admit you must go beyond the limits of SCs as presented in order to make them truly sing).


I've been writing and refining my non-d20, skill based, dice pool rpg for almost two years now with fairly heavy playtesting and revisions along the way. Interestingly enough, it did start as a mini-based skirmish wargame that I wrote in a day and we played and refined for almost two years before someone in one of my groups said, "I'd play this as a roleplay game man..." Enough said, I started writing it the next day. Been going alright so far, we often playtest certain parts until we break it before moving to another part of gameplay just to see what I actually need to write as rules. I have three groups that rotate between d&d and playtesting my game, which still doesn't have a name, I find myself less and less enamored with d&d the more we play it BUT one of my groups REALLY loves it so I continue to DM as requested. My other two groups are very much into my game, which I find funny because there are some of my d&d loving group in both of the other groups that would rather playtest my game at the moment.
This is not my first rpg system, I wrote a percentile based hard sci-fi game while in high school that all my gamer groups seemed to like, it was even played for a few months in our after school game club before everyone started to discover WFRP.


That's my dog, Walter
Every time I think I have a unique idea, it turns out someone already did it. More than writing clear and concise rules, formatting and presentation are the things that would drive me so batty I would never complete a work. Nothing frustrates me more than working on a document in say Microsoft Publisher. I have self published a couple short stories and I never got the formatting the way I liked. The fact that I give up so easily means I should not be in the game in the first place. If I truly had the passion for it I would see it through. I'll leave the writing and publishing to the professionals just like they leave the arm-chair quarterbacking and "if-it-were-me"isms to us rabble.


I've written rules for boardgames, and I've written rules for several RPGs. It really does vary. Probably by personal preference as well. Most of the rpg rulebooks I've written are all encompassing--no separate book for players, GMs, etc. So those are around 300 pages or so, with well over 2/3 of that devoted just to monsters and magic items (a lot of page count goes there, as well as spells). I really try to keep big rule books under 400 pages. More than that, and the heft is just too much and page count is intimidating. My boardgame rules are under 20 pages or so. That's the hardest challenge, as a lot of things go to the cutting room floor. Only the most critical rules need to be in, and things must be kept simple.

Currently I'm working on Chromatic Dungeons (an OSR clone), and I'm up to about 200 pages and have just started monster entries (and still have magic items left to go). Everything else is written. Then again, I'm intentionally trying to keep rules fairly simple, like a cross between B/X and 2e. Give the guidelines and structure, then let the individual GM decide rulings based on playstyle preferences.


Yes, I already wrote four or five different RPG systems, but none with the idea of publishing. Just to take fun with my tabletop friends. Also, I think I do them just for the pleasure of do them and nothing more. A new working system is rewarding for my needs of dopamin hehe.

Of course, not every one of my homebrew systems were really good or even playable. One of them seemed beautiful on paper and a disaster when my tabletop pals attempted to use it. There are others I am proud of, but doubt would be popular because they are very niche.


I've written a few RPG rulesets over the years (some more complete than other), and my current one (The Aurora RPG Engine) is about 4 pages to describe the core engine (or 25 6x9 sized pages in an introductory document that includes designer notes and suggestions for how to hook onto the core engine for different genres/games).

That's just for the engine; I'm playtesting it in a Star Wars campaign right now (to which I am delighted and pleasantly surprised to find is going very well), and the expanded/complete ruleset currently sits at around 44 pages. With full prose and layout, plus adding in the few other items that are missing, I'd say it would probably clock in at around 80 pages or so. Then there would be the sourcebook pages (general NPC stats, equipment, etc) for about another 20-40ish pages.

The "sourcebook" type material of world fiction, lore, magic, adversaries, etc, is often where most of an RPG's page count comes from (something like half the D&D PHB are spells, for example). So a game based on modern day action requires less overall page count than something based on a fictional world with magic or supertech that requires both more rules and more background material. :)


I prefer less is more approach. The more you try to write about something the potential for the user to miss something because they gloss over a giant text block. If you can express your idea successfully in the fewest words as possible those rules are much easier to digest and be retained by the player.


Oh yes. Back in the day, before TFT was a thing, half our player group wrote short rule sets to turn Melee and Wizard into an RPG. In recent years I've finally written up a rulebook for my own RPG. Nothing new in it, and I find it tempting to add/subtract stuff whenever a new rule that I like shows up. Just the old, this is what I want to play sort of thing.


I wrote some 5e stuff for a 3pp, but not my own game (yet). I actually would prefer to make my own setting/adventures, but lack the time to do so; and, I must admit, I dearly love Paizo's Golarion setting too much to set it down.

I extensively house-rule and transplant parts of different game systems together, but I've never considered writing for others simply because it doesn't pay enough to make it worth the effort.


I wrote a 24 Hour RPG some time back. It came to 2700 words or so. I never released it since it was nothing special and I wrote in on impulse.

Having written many reviews on this site back in the 3e days along with some articles for other publishers I can tell you from experience, its time consuming and a lot of work. As such I probably wouldn't write an RPG except as a labor of love since its not going to be better than any game out there now.

If I were writing that labor of love, what Ron Edwards calls a Fantasy Heartbreaker , I'd do it in 3 books either 64 or 128 pages, likely a core rules, companion and world book. Anything more than that would be too much effort to write or honesty if anyone played it, to learn. A few exceptions aside, simple systems like Tiny D6 are the current gaming trend IMO.

I'd guess each book would take several months and frankly in a crowded market, almost no one would bother with them other than my own group if them so it wouldn't be worth it.

Even if I were to use an established system, like say a Fantasy Medieval Christian version of Blue Rose/True 20 I tinkered with a good setting would still be quite intensive to write and the whole thing might come in over 300 pages. I've written that much and it can take months.
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