How to design your own system - in twenty-eight thousand easy steps

ever find your table has so many house rules you can't keep up?
ever wanted to create a truly custom system?
one that is just right ?

me too.

it should be easy right?

OK
I opened this kettle of fish by announcing my long time goal of creating my own roleplaying system.
I clearly had not thought it through as thoroughly as I thought and so, here I am.

Any one ever make their own system? Ever tried and failed, or gave up?

experience is valuable.

maybe we can think more about HOW to go about creating a new system, before we try to actually create a new system.

Any sage advice for a first step?

First step I took when I created one: open a notebook, paper or otherwise, and write your goals. Is it too be a simple or complex system? Is it universal or setting specific? What do you want the players to do? Is there a similar game you want to use for inspiration?

Next I'd try to narrow it down. It's easy to fill in the holes around a precisely defined project, and daunting to try and think of everything. Even if you want a universal system, I think I'd be better off if I start with a simple use case first. You can expand and generalize later.

Third, get a water bottle to squirt all the naysayers who say: why create a new one when there are so many? Luddites, all of them, pay them no heed!

Have you considered just using a hack of 5e instead of making a whole new system?

Runs away laughing, Nyul nyuk nyuk nyuk...

I have created several!

All to varying degrees of success- the first one I made in high school was basically just D10 roll and add it all together vs. target number or opposed-- very simple, except it was based in my novel of the time so the races and magic were kind of unique but really open ended-- you just had a skill in like "geomancy" and then said what you wanted to do with it and rolled. . .

Several others along the way that are less memorable, tons of house ruling of various systems. . .

Second fully fledged system I made (not entirely) was a d20 system-- inspired by Monte Cook's Arcana Unearthed and based in a world I designed where the Sun is basically a mono-theistic deity and all characters were divided into "Sunned" and "Un-Sunned" characters-- it was based on Persian and other "non-western" myths/lands and twists of my own with all custom races besides humans- Silla Jinn (PC tier genies), Parua (mouse people), Pitr (big humanoids inspired by Marids- pearls for teeth, seaweed for hair), and Dokkaebi (kinda monkey/dog people who talked in a really bizarre pattern and cut their tails off to use as maces/wands), and with all custom classes one for each attribute for Sunned (Scout, Champion of the Sun, Servant of the Sun, Loreweaver) and un-Sunned (Denier, Hermit, Wanderer). . . played only a few sessions in it, not even enough to playtest it really-- I still really like the setting I was writing for it, and I think that the classes all work in principle, but the big stumbling block was that it required custom spell lists for like 4 different classes-- and I wanted to reuse as few spells as possible, so I just never could write enough spells to have it finished. (And also-- it was d20 game based on 3.0 then kinda updated a bit to 3.5, but kinda just at a weird time that was between the two)


The third one-- my "Core 8" system is a d8 based skills based system that I've used a few different ways (for a Sherlock Holmes game, and a Sci Fi game most notably)-- I still have faith in this, but it's not really super unique mechanically-- the core concept is you have skills, roll d8s for each point you have in a skill, and 6+ is always a success-- but the twist is that at certain levels of a skill you'd get an extra die-- first an extra d6 (but 6+ is always a success, so worse odds than an extra d8), then an extra d10 (slightly easier to get 6+ on a d10), and then just a "free success" when you maxed out-- then it was against target numbers that were number of successes-- 1 for a routine thing, 2-5 for difficult tasks, and of course, opposed rolls-- it needs playtesting which I may get to eventually.

Anyways, yes-- yes I HAVE done it to varying levels of complexity and completeness over the years and I am sure I will again.

I've considered creating an Ironsworn/Starforged hack, but there's already a wide variety of those out there. And they're likely made by folks who are far more clever and hard-working than me.

(I also dislike crunchiness and math, so any system/hack I devised would likely be janky.)

I've also bounced ideas off AI chatbots, but never formed anything concrete.

Still, some thoughts:

I'd consider first focusing on the macro. What are the core tenets of your system? Is it rules-lite or mega-crunchy? Is the expected setting fantasy, sci-fi, or what? Will the players mainly be adventuring in the wilderness or dungeons, or are interpersonal relationships/diplomacy a key feature? Etc.

Now that you (hopefully) know what your system is, you (hopefully) know what it isn't.

Consider those video games that try to do everything at once, but end up being bloated, buggy, walking simulators. (With predatory micro-transactions, but that's another topic....)

Then consider those games with tight gameplay. Slay the Spire comes to mind. It knows what it wants to do, and does it exceptionally well.

But maybe your goal is to create the "ultimate system," with every possibility considered. If so, I [shudder] wish you well! 😬

I have created several over the course of my 20+ years of adventures in gaming. More recently, my newest system, Fables & Foxtales, is presently in playtesting!

Do I have any advice? Yes, absolutely! Here are my thoughts.

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Suggestion #1: Make a game that you want to make. People who make truly good role-playing games don't do it because they're looking to get rich, famous, or because they want to make their game popular. They do it because they're unsatisfied with what they've played and thought, "I wonder if it would be more fun if _____." They're the thinkers, the schemers, the dreamers who refuse to settle for something 'good enough'.

Maybe the games of today are missing some important facet or role-playing that you want to explore. Maybe you have a brilliant idea for a mechanic that you think could revolutionize things.

Whatever the case, always keep your enjoyment and interest front and center, because the moment you start making games for any other reason is the moment your spark starts to fade. Worry about whether or not others will enjoy it after it's done!

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Suggestion #2: Start small! As others here have already suggested, consider making a 'mod' or 'hack' of a game that you already play. Fables & Foxtales started off as several hacks of different systems (D&D 5e, Ryuutama, PbtA), which I took pieces from to form a larger, more cohesive whole. Starting with a hack or a mod lets you learn how to 1) create new rules, 2) learn how to expand on existing rules, and 3) figure out how to balance things.

Once you've done this a few times, then try an build a new system.

Additionally, don't be afraid to 'borrow' things to make what you want to work, work. Some of the most popular role-playing games out there were born from the bones of other games. It's totally fine to want to port in the parts that you like. Not every part of the game has to be wholly unique.

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Suggestion #3: Make some friends! You'd be surprised how many people out there are interested in game design, but aren't really the type of people to jump into it. Moreover, there are tons of other game designers out there, and there's nothing we like more than talking shop about our systems.

Designing systems requires a sounding board, whether that's potential players, other designers, or maybe even someone from outside of the hobby who can give you a new perspective.

However, at the same time, make sure that your idea stays yours. Getting feedback or suggestions is fine, but to reiterate the first point, make your game first, and then refine it based on your playtests.

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Suggestion #4: Keep a log. I personally keep a dev journal that I make entries in for major milestones, or just whenever I feel like rambling into the ether about my creations. Only a few people will actually read it, but that's alright. It gives you something to look back on and appreciate the achievements you've made.

Moreover, it can also serve as a sort of To Do list, roadmap, or some other tool to help you keep on track to your goal.

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Suggestion #5: Play lots of games! This may seem counterproductive because you're trying to make your own, but trying new games and finding their flaws is what likely made you want to make your own game in the first place. Use that dissatisfaction to power you forward!

Moreover, the more games you try out, the more it will help open up your perspective of what rules can look like and do. I don't personally think there is such a thing as an 'ultimate' game that everyone is going to like, but if you stumble across something and think "oh, that's actually really clever," then there's free inspiration staring you in the face.

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Suggestion #6: Take. Your. Time. The funny thing about me is that when it comes to life, adulting, and a job, I'm kind of middle of the road. I'm not terribly ambitious, and I'm generally fine with mediocre output, so long as it doesn't get me in trouble. When it comes to game design, though, I am a workaholic, and I have spent many a night on caffeine-induced spells trying to cross things off of my checklist.

The simple truth is that game design is a process. It takes time. A lot of time. And any time you commit to a big project, you're going to put a lot of yourself into it. Time, energy, and emotional stability. And eventually, if you aren't careful, you'll burn out. I cannot count the number of times I have worked on a game so hard that I gave myself a headache, or hit a point where I would try to do something, only to just stare at the page until giving up.

You need to have the right mindset when you work on a game. Eagerness will only get you so far; you have to also be inspired, efficient, and you have to set yourself up for success. Eat something energizing, watch a show you've been meaning to watch, take a nap. Do what you have to do to take care of yourself, and when you can't seem to get anything else out, take a break, do something fun, and come back to it later. It ain't going anywhere, and trying to force yourself to do it will only result in a bigger burnout.

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Suggestion #7: Have a good, strong goal in mind. It doesn't have to be refined, detailed, or exact. In fact, it should be broad, mutable, and easy to turn in a new direction. When I started Fables & Foxtales, I did so because I was tired of games that focused on being good at one thing, and everything else being resolved with simple, depthless checks. I wanted a system where I could change the mechanical focus by the game I wanted to run, whether that was a war drama, a high school rom-com, a cozy rural fantasy story, or a Victorian court drama.

So that became my goal, and the rules were shaped according to meeting that goal. With a lot of trial and error and headache, I might add.

The point is, having that goal in mind is a focal point. It helps you stay grounded, and as long as you keep it in mind, you'll continue to question things, refine things, and change things completely. But in the end, you slowly get a little bit closer to what you're trying to do.

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Suggestion #8: Plan ahead! I've said that before, I know, but honestly, the best thing you can do for yourself is to leave yourself room to expand, and don't write anything 'final' until you're ready to present it. Eventually, these things are going to get big enough that you start to misplace things, or you wind up forgetting something you set in stone before, only for it to come back and bite you later.

Case and point: recently, I've been learning how to code for Google Sheets so that I can make a "campaign/setting wiki" that imports data from a master document. Initially, the thought was that I'd have a tab for each campaign I plan to run in the near future, but all of these games also took place inside of the same world, so there was also a table for Universal games.

The problem I didn't foresee was "what if I want to run a game in the same geological region as another game, but didn't want to include the minute options for that game specifically, like NPCs, settlements, and other things that would have zero consequence in the new game?" What I should have done in the first place was have a 'Universal' tab for things that applied generally across the world, and then tabs for major 'Settings' that I planned to use. And then have tabs individually for things that were specific to each game.

I went back and corrected them, but this is an example of a time when I should've had a little more foresight and thought ahead about what I could do to save myself time and energy and the need to take an aspirin.

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Suggestion #9: Review, Review, Review! Going along with the previous point, game systems tend to get quite large, and it's not always easy to remember this or that. That's why you should make an effort to regularly stop, go back, and re-read bits and pieces of your work so far. The more you do, the clearer that picture in your mind becomes, and eventually it'll be second nature to you.

You can help yourself out in other ways, too, like by putting reminders of important facets where they're easy to see, like post-it notes on your screen, a corkboard of diagrams, charts, or inspirational art that reminds you of the game, making lists of features or creating a practice "table of contents".

The more you keep your system in your mind, the more you'll think about it; and the more you think about it, the better you'll understand it, and the more you'll find yourself excited to work on it!

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Anyway, I hope some of that helps. I imagine some of it is probably somewhat self-evident, but I think it's important nonetheless. Just remember that creating a system probably isn't something you're going to be able to create quickly. I've been working on my game for probably close to five years now, and it has been a wild ride full of rewrites, revisions, and more than a few periods where I needed to just step away from it for a few weeks or months.

That said, if you're committed to the idea, then I truly hope you find joy in creating games as I do! It's really a lot of fun in and of itself, and the payoff when you actually get to play it is a wonderful feeling ^^

wow
I feel like I've signed up for a college course and they forgot to ask me for tuition!

I've been dabbling with my own system! Mostly a hack of Black Sword Hack, but I've found that coming in with a clear vision of vibes and intentions can be a good start. Even as the inspirations have changed, many of the rules have changed with them.

I think one of the biggest questions is about the intended characters, how successful they are meant to be, and the dice resolution system that will get them there. I've played 2d6 systems where you are meant to succeed with a cost, and I'm currently playing a 2d6 system where you are expected to fight for every success. The d20 is quite different between various editions of D&D, and the stories and heroes tend to be different because of it. Do you like the d100, where the dice resolution system is based on a fully fleshed character and all of their knowledge and skills? Do you want to abstract the resolution into d12s that represent hope and desire instead of actual training?

For mine, I've settled on a d20 roll under but roll high (blackjack) system. It has solved a lot of problems for me, and seems to be fairly unique. It has allowed me to add degrees of success, and leaves room for modularity in the future. It has also allowed some fun gambling with d6 modifiers, where you might push your luck too far.

lets see if I can create a bit of a summary/list:

1. SUPPLIES : notebook - squirt bottle
2. STATE GOALS : to create a RPG system that will see me through my gaming life (too big I know)
-as simple as possible, but still universal (how hard could it be?)
3. NARROW IT DOWN : excellent advice. Expand later.

thank you Qralloq

4. START WITH A MECHANIC - create a new mechanic that fits in your current system. Then add another.

I like this idea. I am currently planning a campaign around a ship. I played one game of Starfinder a while back, and it really opened my eyes about how fun a ship can be. I'm a life long D&D guy and 2e's "Of Ships and the Sea" was great for ships, but not much for crew. It just recommends hirelings. 5e's Ghosts of Saltmarsh had more. But not enough for me. So that will be my starting line.

thank you Alordis

5. CONSIDER THE MACRO : eventually, I would like a universal system. But I want the focus to be the characters, not the world. The interaction between players is my favourite part of role play. It can be very difficult to get players to interact with anyone besides the GM. But the best games ar GM light. The players create the real story between them. I want a system that encourages that.

thank you Totes_McGee

Very true. "Waiting around for the GM" is a problem...

...which is why I play co-op Ironsworn/Starforged! (Yes, I'll always hype this system.)

So you want more player-to-player interaction. Do you want to "force" this with mechanics? Like maybe each PC is cursed, and the curse only weakens when they connect with each other?

But now you're talking less about the system, and more about the setting. Ideally, the system should encourage player co-operation, but not require it and certainly not railroad it.

I've been thinking about your attributes problem, and I keep coming back to a mechanic that was unique to a game I played back in the day. Mayfair Games created the DC Heroes Role-Playing Game. For their attributes, they needed a system that allowed Superman to interact with Batman, yet both use the same scale. The idea that they came up with was unique. Each rank of an attribute was double the one before it. Thus, a man with a Strength of 3 was twice as strong as a man with a Strength of 2. It is explained in more detail here. It let Batman (Strength 6, IIRC) stand toe to toe with Superman at Strength 50. Perhaps something similar to this?

Yeah I’ve made a few. Some are hacks of other games, while others are merely inspired by a few games. Most exist in either the OSR or PbtA space.

Most I made for a lark in a few hours. If I’m more serious, I usually think backwards, starting from the feeling or emotion or experience I want to engender at the table in players, and then work backwards to system. Here are a few of my sillier designs, if you are curious.

https://drgwenmarshall.itch.io/

My more serious stuff usually is a collaboration with a game publisher who will handle marketing and distribution. I’ve done that work for my own publications in the past and it is a pain in the ass!

The secret to being a successful writer of any sort, including game design, is the magic of Butt-In-Chair. To be a good writer, you must write. A lot. To be a good game designer, same thing. Log the hours. Specifically: sit, write, revise, solicit feedback from readers or play testers, revise, repeat. This iterative process is FAR more important that your initial concept.

I was dissatisfied after some years of playing with the available systems, so I tried it in the eighties to construct a more fitting system. It didn't work out well, because I didn't knew enough. I made a second attempt in the nineties – that didn't work either, because I had focused too much on what I didn't want.

So I tried again in the 2000s and managed to write a system within three years that I still play today. This time I had two decisive advantages – I was already familiar with many systems, this time I knew what I wanted and I was able to change the parts which didn't fit well to the whole.

In terms of working methods, I was pretty much on the same page as @kaekozee.

If you're just creating a private system to use among friends and players of your campaigns, then yes, as long as you have your objectives clearly cut out, it isn't too difficult to design a RPG system to run your games on.

It all depends on what you intend to work with, and do with the system and what you've worked with before, and also what your players want in a system. The players needs have to be considered in work on the system, because if it's not useful to them, and doesn't make it more playable for them or solve some major matter for the players, there's no point in embarking on the venture, so player input and perspective is particularly important in constructing a system.

I know a lot of GMs that go out to develop a grand idea of a system, and forget about the players in the whole aspect of creating a system, but playtesting and input from players is paramount. If you're not solving problems from some other situation and system, then you might as well revert to that system.

In other words, if it ain't broke, don't fix it. Just good design advice in general.

I've designed a system based on play issues I've seen with groups I've played with, but I haven't really done much with it, because there are many systems already out there and with the rule of not introducing something if other systems aren't really broken, I've found it difficult to argue with some of the basic systems, because while alternate rules would work, just as equally changing GMing style has also just as much changed how game dynamic works, too.

Precisely the reason I haven't done my own system yet. I found one that works for everything I need to do, and I use it (Savage Worlds, if anyone is wondering).

6. carrots GOOD - sticks BAD

never railroad players. Nobody wants to be stuck on a track.

7. MAKE THE GAME YOU WANT - don't fall into a trap of popularity, or profit. Make the game you want to play, because you want to play it.

8. START SMALL - AGAIN - make a small mechanic. Play it. Then make another small mechanic. Get a few little projects or hacks under your belt before trying to create a whole world

9. COLLABORATE - get some friends who also want to create a system. Work together.
check! you guys want to be my friend - right? ;)

10. PLAY LOTS OF GAMES - I'm trying, I'm trying... Honestly, I have traditionally avoided multiple systems, choosing to specialize over generalize. But my mind is open now, I plan to apply to more "beginners welcome' games in the Tavern

11. TAKE.... YOUR.... TIME - well, I've been working on this off and on for almost 40 years. So, check.

12. HAVE A STRONG GOAL - this one is tricky. I have a goal. A complete, perfect, universal rule system for any role playing I may want to do now or in the future. Simple right? (twenty-eight thousand steps may not be enough)

honestly, I'm hoping for a system that focuses on character development, while being able to answer the questions those characters will have in their world. My favourite parts of video games are character creation and exploration. That's where I like to spend most of my time. So, I think my goal is really a robust character creation system, that has what's needed to let those characters explore and develop.

13. PLAN AHEAD - yup. Paramount. I wrote a novel once, before computers, and I planned out the skeleton of the story into 9 parts. Then I glued nine manilla envelopes to a piece of bristol board (man, I'm old) and anytime I had an idea, I would jot it down and stick it into the appropriate envelope. Every week, I would empty them and put them in order to record them. Has Apple made iBristolBoard yet?

14. REVIEW - REVIEW - REVIEW - I'm going to start by re-reading this forum. Man, my jokes are lame, you guys are saints for putting up with me.

In review, my plan is to start with a "hack" for AD&D that clarifies and improves the rules for life on a ship. Focusing on crew roles, role playing life on-board instead of just going for a ride.

thank yo SO MUCH kaekozee
I know how much time it took to write all of that, and I cannot tell you how much I appreciate it.

Have you played, GMed, or hacked any of these systems (especially in a swashbuckling/pirate setting): GURPS, Cypher System, Cortex Prime, Basic Role-Playing (BRP), Fate or Savage Worlds?

In my opinion, every one of them has valuable lessons—things worth copying and things worth avoiding—when designing a generic RPG. I’d strongly suggest trying each at least once, even as a one-shot.

GURPS in particular, run in a pirate setting, can be a real eye-opener. You may end up loving it… or hating it. 🙂

You're welcome! Happy to help! ^^

If you're looking for inspiration on character creation, then if nothing else, I would suggest you just go through and make a character or two from various systems. That's my first step to learning how to play or run a new game, and I always find it to be a fun way to explore at my own pace.

For suggestions, take a look at the way Traveller does it. It's famous for having an intricate, procedural character creation system where you basically get to simulate living out your character's background. I was really inspired by it, even if I barely got to play the actual game. Legend of the Five Rings is another, as who you are, where you come from, and what you can do are all important facets in the world, so there's a lot of depth and significance to character creation.

I think we share the same goal in that regard--I build my game so that "stats" are static, and you have to pick two stats to roll vs challenge checks. The only way to change or manipulate those rolls is by drawing on things like relevant skills, personal ideals, and bonds with others, all of which are limited in scope, so character development and growth winds up being a pretty important facet to how the game is played. :3

Though if I'm being honest, at this point I'm beginning to wonder if what I made is less of a game and more of a cooperative storytelling platform 🤔 Oh well! I love it regardless ^^

I did over six years ago when I decided to create my own world setting based up the Warhammer Fantasy Universe called Warhammer Fragile Alliances.

It has been a great success and has achieved what I was hoping to achieve in terms of game play, and the players who have explored my world have said they enjoyed it. The biggest problem I've had is finding suitable hosting sites and since Tavern-Keeper.com shut down I've been struggling to find a suitable hosting site that provides the same features. I was hoping Gamers Plane might work but the lack of a post comment feature has left me lost for a solution.
I think the main thing to consider is 'Why am I bothering?'

It's an awful lot of work and so you really need a very good reason for bothering to start.

For me it was the desire to bring together the aspects of the Warhammer Universe that I felt were the best versions of this franchise which is now fast approaching it's 5th Edition plus the clone versions. So, I wanted to create a definitive version that combined the best aspects of every iteration into one plausible and rational world setting.
Make sure you have a good reason for bothering and write it down so you don't forget it.

Keep a clear distinction between the 'Fluff and the MetaPhysics' of your new world. You can have fun with the 'Fluff' but the 'MetaPhysics' have to be consistent, universal and make sense.

I'm trying to stay in order here, but that is a GREAT idea. I like making characters as much as I like playing. Maybe more. Gamers Plane just so happens to have a large repository of character sheets!

15. MAKE CHARACTERS - lots of 'em, from lots of systems. Collect the best bits.