Recently, there have been a number of releases that bill themselves as “setting-neutral,” meaning they have mechanics that could work with any setting published or with a setting of your own design. Homebrew has been a huge part of roleplaying games, probably ever since someone in the mid-70s took a look at a published adventure and thought about a tiny tweak. On the other hand, you don’t have to go all out. Some of the best homebrew creations are just simple adjustment of a system for a particular gaming group’s preferences.
That’s not really what I’m doing here, though. Here, we’re creating worlds.
These systems are all designed to make it easy for you to build your own world. If you’re reading this looking forward to the part at the end where I tell you which one is best, that’s not happening. Sorry. The truth is that all of these are great systems (otherwise I wouldn’t be bothering to review them) but their strength depends on what sort of game you’re playing. Sure I have favorites, but that’s because they match well to the types of games I like to play. And I wouldn’t necessarily go with an objectively preferred system for a new game if it didn’t match the feel, design, and qualities of the world I’m trying to emulate.
For each of the games below, you’ll get a brief overview of the mechanics, a bit about what it does well, some about what the pitfalls of the system are, and then some ideas for the types of games I think it would be great for. If you’re going to buy a hardcopy of these, by the way, consider doing it through the link provided to support our site! Now, without further ado let’s get on to the reviews.
AGE System
Core Rulebook: Fantasy AGE RPG
The Mechanics:
What It Does Well:
Potential Issues:
What To Use It For:
Burning Wheel
Core Rulebook: Burning Wheel RPG by Luke Crane
The Mechanics:
What It Does Well:
Potential Issues:
What To Use It For:
Cortex
Core Rulebook: Cortex Roleplaying Game System by Margaret Weiss Productions
The Mechanics: The core of this system is dice pools, but of a different sort than most dice pool games. You assemble a dice pool of different sizes and roll against a total. There aren’t modifiers or training bonuses, instead the more trained you are the bigger the dice that you roll. A scrawny kid might have Athletics d4 while a muscle-bound warrior has Athletics d12. They both could roll a 4, but the warrior has a much better chance to roll higher.
What It Does Well: This system does an excellent job of balancing ease-of-creation with intricacy. You can create simple powers or ones that work in complex ways, depending on the players’ preferences or the setting’s needs. NPCs and other threats are easy to create as well, sometimes just as a single die or a group of dice, which means it’s easy to create and adapt on the fly.
Potential Issues: The use of complications and assets to give game mechanics requires keeping track of a lot of moving parts. A constantly changing constellation of different conditions is best monitored with index cards or a reference sheet but it can get a little overwhelming in complex situations. The solution of limiting these things doesn’t work well for everyone depending on the story. Items also tend to be a single die added to the pool (if that) so they can be McGuffin-type bonuses rather than intricate artifacts.
What To Use It For: High-powered settings such as superheroes, demigods, or werecreatures work especially well in this system. This also works for people with skills and abilities that aren’t necessarily hyper-powered gods or anything. Spies with powerful skillsets and resourceful thieves would work just as well. This also works well for growing settings that may need quick game mechanics for groups that head into new areas.
Cypher System
Core Rulebook: Cypher System Rulebook by Monte Cook Games
The Mechanics:
What It Does Well:
Potential Issues:
What To Use It For:
d20 Modern
Core Rulebook: d20 Modern Roleplaying Game: Core Rulebook by Wizards of the Coast. Rules are also available as an SRD for free.
The Mechanics: It’s relatively easy to explain the mechanics of d20 Modern, the genericized counterpart to Dungeons & Dragons 3e. Like all d20 games, you roll 1d20 then add whatever modifiers apply and compare it to difficulty classes. There are six basic classes that correspond to the six base attributes of characters (the Smart Hero favors Intelligence, the Tough Hero favors Constitution, etc) which allows you some really wide berths in character design. After that you might qualify to advanced classes (the equivalent of prestige classes in D&D 3e and paragon paths and epic destinies in D&D 4e).
What It Does Well: The system is almost stunningly straightforward and there’s tons of material to pull from. If you can’t find what you need in the d20 Modern Core Rulebook, the Menace Manual, the Urban Arcana magic sourcebook, or the time period sourcebooks of d20 Past, d20 Future, d20 Apocalypse, and d20 Cyber (near future cyberpunk) then there are tons of third party sourcebooks and the entire collection of D&D sourcebooks.
Potential Issues: This system was not built for world-building at its heart. It was built for D&D and does an awesome job, then adapted for a more generic version but the system still has a lot of moving parts. If you want to create a new advanced class, new piece of equipment, or(worst of all a new subsystem (like superpowers or new alien races) then you’ve got quite a bit of work ahead of you and some playtesting to balance it. However, these are easy enough to avoid if what you want is already similar to an existing d20 option, and there are libraries of this kind of thing.
What To Use It For: Tactical games with a lot of precision and options. There is a lot of material out there and the whole of D&D 3e and 3.5e to adapt to use.
Fate
Core Rulebook: Fate: Core System by Evil Hat Productions
The Mechanics: The dice-rolling for Fate is bounded-everything, meaning challenges cover the same numeric range (-2 to 8) throughout the whole game. You have abilities that are rated over the same range so when you come up against something you check your score against the problem’s (“The trap ahead of you is a +2 pitfall, but you’ve got Athletics +3 so no problem”). When you can’t just blow by a challenge with an auto-success you roll set of d6s that will give you a random modifier of -4 to +4 (usually -2 to +2) and that’s typically the whole roll.
The really nice part of the system is the aspects, which are where the world building really shines. Your character has some skills they’re good at but most of their abilities come down to their aspects which might be things like “On a holy mission” or “Has a cybernetic eye.” If one of your aspects comes into play, you can add another small modifier to your roll, lower the difficulty a bit, create a help for yourself or others, or something else fun. Everything else in the world also has these aspects, though, so you might be in a lab space that is “On the bleeding edge of science” facing off against goons that are “Zealously devoted to the cause” in a country where “Big brother is everywhere.” The point is, you’re not the only one who will be calling in modifiers…
What It Does Well: This system’s strength is definitely the character and setting creation. As they say many times, character creation is part of the gaming process and players work with each other and the GM to build stories from the start. If your setting is a little freeform, either in the gross concepts or the fine details, this collaborative process can short-cut the arduous creation steps of getting from your imagination to the table.
Potential Issues: This system works for already-imagined settings as well (or games based on your favorite book, movie, etc) but the details of the system are slight. This is not to be confused with “the system is light,” but it does mean that most parts of the setting will be of the “up to the discretion of the GM” type. For settings and games that are being newly formed, of course, this is not such a bad thing but it does mean that there are few things that GMs can lift into their games and then leave. If you borrow the magical items from Dresden Files and the cybernetics from NovaPraxis, you still need to think about when magic can apply and when it can’t. Also whether magic is detectable by cybereyes. Also what the actual means of data storage is, should that come up. You get the idea…
What To Use It For: If you have a basic seed for a setting and just want to run with it, Fate definitely has your back. Players take on a lot of the responsibility for filling in details (annoying for some GMs but also a great help), leaving you to concentrate on the story itself. If you’re using someone else’s setting you’ll have to do a little work ahead of time, though the aspects system will save you some hassle. Once you have the overarching themes, though, you can leave the fine details to players. This is the case with the Dresden Files, where the themes and organizations of Jim Butcher’s world are detailed but players build their particular city alongside their GM.
GURPS
Core Rulebook: GURPS Basic Set: Characters and GURPS Basic Set: Campaigns by Steve Jackson Games
The Mechanics: The Generic Universal Roleplaying System (GURPS) has been published for twenty years and is the original settingless system, as its name suggests. The basic GURPS mechanic is both simple and familiar: roll 3d6 and compare it to your skill after modifiers. Equal or lower is a success, a somewhat-backwards way of thinking but familiar to anyone who’s played AD&D. Everything in the game works this way, and actually the only dice used are six-sided ones so getting up and going with GURPS is pretty easy. The universality and strength of GURPS comes from the modular system that goes with it where you can add in tactical combat, magic, sanity rules, cyberpunk mechanics, alien races, and anything else they’ve written.
What It Does Well: GURPS is simple and straightforward. If you want to include horror elements, get the Horror book and add liberally. The authors also do a really good job of being transparent about their design of the rules and the system has been in production for decades so there’s a lot of support for new GMs.
Potential Issues: Making your own GURPS rules is a lot easier than adapting many games, but it’s still a lot of work. Expect some work ahead of time and some playtesting during the campaign before things are totally smoothed out. Like a lot of game systems that have been around since the 1980s, the game mechanics are a beautiful but fickle assembly and new additions have to be “felt out” before they become well-integrated.
What To Use It For: If you’re making a game world that you don’t have a clear image of beforehand (especially when you have a genre or broad-strokes idea rather than a specific series or complicated idea) then this might be the system for you. It’s simple and has a lot of resources for it that strike that old chord of simulationist design with a very “handmade” feel (think original D&D and AD&D). I’d also recommend this system for GMs who have a game world that they want to create and they don’t necessarily want the creation to be a joint venture. Using the optional systems of GURPS, you can make a gameworld that fits your needs and then hand it to the players for them to make characters in with plenty of options within the framework you’ve set up.
Savage Worlds
Core Rulebook: Savage Worlds Deluxe: Explorer’s Edition by Pinnacle Entertainment
The Mechanics: Abilities in Savage World are measured in dice size from d4 to d12, with an average is d6 (similar to Cortex though without dice pools). Characters roll against Target Numbers
What It Does Well:
Potential Issues:
What To Use It For:
One-Roll Engine
Core Rulebook: Wild Talents: Essentials Edition by Arc Dream
The Mechanics: For players used to D&D, this one might be the hardest mechanic to understand. The learning curve is very shallow, though, and the core mechanic of the game can be summed up in two easy sentences. First, roll a pool of d10s and group the results into matches to get result options reported as number of matches (width) by number rolled (height). Second, pick the matched group you want to use (assuming you have at least one) and that is going to tell you how quickly (the width number) and how well (the height number). There, now you know everything you need to play an O.R.E. character.
What It Does Well: O.R.E. strikes an excellent balance between abstraction and specificity. Each ability adds to the narrative by being broad enough to interpret how you want but the hit locations and injury rules mean that you can let the mechanics do the talking if you’d rather. The basic mechanics are also easy to learn but there are so many different directions to go in that each character’s abilities will feel interesting and unique.
Potential Issues: The basic mechanics are easy to learn but creating abilities is difficult. O.R.E. products come with lists of ready-made abilities and this is critical because making your own can be pretty challenging. There is a steep learning curve to get into the nuts and bolts of the system, although you can do a lot once you’ve got a feel for things, and this can be a barrier for new players.
What To Use It For: The system was originally designed for gritty, harsh, superpowered combat and that’s still where it excels. More recent adaptations like Better Angels and Monsters & Other Childish Things have expanded that somewhat but this system will be easiest to use with fights and abilities that are meant to have definite consequences and where the power spread between haves and have nots is wide.
Ultramodern4
Core Rulebook: Ultramodern4 Core Rulebook by Dias Ex Machina Games
Rules are also available as OGL for free.
The Mechanics: A similar option to d20 Modern, this system is a modernizing/genericizing version of Dungeons & Dragons Fourth Edition. This means that while there is only one sourcebook (or three, if you count the Amethyst game that inspired it and the NeuroSpasta cyberpunk game that grew out of it), there are mountains and mountains of material to pilfer from between Wizards of the Coast products and third party sourcebooks. The basic classes are modern alternatives to the basic classes from 4e but the write-ups and party roles are all the same (no power sources for these, though). The faceman, grappler, gunslinger, heavy, infiltrator, man-at-arms, mastermind, sniper, specialist, techie, and vanguard are all familiar-enough terms that players should catch on quickly and the power options make character design extremely easy, even at higher levels. Plus new rules interpretations make the switch from fantasy to gritty easy on the DM.
What It Does Well: The system is modular and easy to adapt to a particular setting. It has abilities and classes for all different sorts of characters and you can draw on other 4e sources to expand on it. The near-future tech material from NeuroSpasta is also a great addition for any sci-fi games that need robots and VR.
Potential Issues: This book is based on Dungeons & Dragons 4e which means it’s very tactically-based. You can do it without grids and maps but it’s harder, and the focus of the classes is combat over other situations. You don’t have to play a soldier in this but scholarly classes and people have abilities that gives them combat options as well meaning, for better or worse, everyone is combat-ready.
What To Use It For: Tactical games where gamism trumps customizability. Even using the material from D&D 4e there are fewer options and manageable limits in place.
Mephit James Blog 