Universal System

A Game System that can, in theory, be used to play a game in any setting.

Universal systems are good in that if you want to switch genres you don't need to do much more than the standard preparation for a new game. You already know pretty much everything you need to about the rules.

However, universal systems in practice tend to be better at some things than others. This is especially true if the system was not originally designed as a universal system but grew into one over time. In particular, a number of 'universal' systems -- especially the more complex ones -- turn out to support basically human characters best and increasingly break down the further a character or creature is removed from that default assumption. (Obviously, this is mostly a problem for groups trying to play in more fantastic genres like comicbook superhero action or, well, fantasy.)

Some universal systems are also generic, meaning they can be used to play any style of game, from near-freeform roleplay, to fantasy dungeon crawling, to equipment-focused tactical play involving tons of preparation. The difference here is not in the subject or setting of the game, but in what the players have to do in order to play it. This type of Game System needs to have a lot more rules than any particular game played with it will need, so generic systems will usually be "modular," meaning that optional rules can be easily added and removed from the game as it is convenient to do so. It usually isn't possible to design a game so that none of the rules are mandatory, so generic Game Systems conventionally have a small set of rules designated as "core" rules. These are often distributed separately from the optional rules, sometimes in multiple versions of varying depth; for instance, the sixth edition of HERO offers a "lite" edition for free, a Basic edition in softcover that omits the more esoteric options, and the full rules in hardcover.

Tabletop RPGs in general have been using Universal Systems more often in recent years, and many game designers who are designing a system from scratch for their particular setting will nonetheless give it some qualities of a Universal System, such as simple, general task-resolution mechanics, and combat systems that work the same regardless of the particular actions the combatants take. The system in question might never be released as an independent system, Universal or no, but the same things that make a system Universal also make it easy for Game Masters to use the system in precisely the way they want to. Game Masters tend to like this.


 * Basic Roleplaying (Call of Cthulhu)
 * Pros: Uses percentile dice, meaning you can easily tell what percent chance you have of success for any given roll; easy to learn.
 * Cons: Limited material.


 * D6 System (Star Wars, etc.)
 * Pros: Simple, adaptable core mechanics; easily learned and customized; available free under SRD; low gratuitous complexity, meaning little maneuvering room for munchkins. Works for almost any setting.
 * Cons: Skill advancement has never really worked; the scaling system sometimes produces strange results; feels samey. Makes almost any setting feel like The Thrawn Trilogy, so not truly "generic". Little support compared to GURPS and d20.


 * D20 (D 20 Modern, Dungeons & Dragons, etc.)
 * Pros: Sheer number of books (especially fantasy ones), most famous game on the market, easy to make a character, easy to guess approximate odds of success. Core system free online.
 * Cons: Level-based system, mostly fantasy. Lends itself to being broken, as it's almost always possible to get enough bonuses to make important rolls trivial. Often uses multiple dice of varying sizes.


 * FATE (Strands Of FATE, Spirit of the Century, The Dresden Files)
 * Pros: Most of the virtues of FUDGE (which it's based on), but with more clearly defined rules that leave the GM improvising less
 * Cons: Most of the flaws of FUDGE, too.


 * FUDGE
 * Pros: Simple statistical model, freely available, informal design actively discourages rules-lawyering and munchkinism.
 * Cons: Not commonly played, not a whole lot of material, open-ended rules require the GM to do a lot more prep work before beginning a campaign, either uses hard-to-find FUDGE dice or makes you read six-sided dice in an unintuitive way.


 * Fuzion (Artesia, Cyberpunk v3.0, etc.): A blend of the Hero System and the "Interlock System" used in Mekton and Cyberpunk 2020.


 * GURPS
 * Pros: Sheer number of books, very well researched, quite internally consistent, tons of skills. All success rolls are against the character's skill modified by the situation, meaning there's no need to arbitrarily determine the number to roll against. All success rolls are on 3d6, giving a realistic probabilistic curve. System is designed to be very modular, adaptable, and customizable, with most rules being optional. Combat actually moves pretty quickly once you get used to it, since a lot of the "standard" modifiers are prefigured. No levels or class restrictions. Basic "Lite" rules free online.
 * Cons: A lot of point-juggling (4th edition offers a lot of templates, but they aren't exactly easy to read), 3rd edition vehicle rules. It's easy to get situations with tons of modifiers, bonus and penalty. Character creation can be very intimidating from the sheer breadth of options and skills, especially without GM help. Balance issues at very high power levels. Not as "universal" as is advertised, as the base system has required new rules added to it for every new genre or setting for it to work.


 * HERO (Champions, etc.)
 * Pros: Open-ended, user-defined power system based on effects rather than causes, which provides internal extensibility — like a programming language, one can even use the Hero System to simulate other game systems' mechanics. The rules are designed to scale to ridiculously high power levels, while still functioning reasonably well at normal power levels. Lots and lots of optional rules that are truly optional, so players can fine-tune the "physics" of their game world if they want to. The base rules work just fine regardless of setting or genre.
 * Cons: "Big grained" scale, where attribute/base skill rolls only have 4-5 meaningful values within human norms; abbreviation-dense jargon ("4d6 NND EB, 0 END, OAF"); number-crunchy character creation (at least when powers are needed); lots and lots of optional rules ...


 * Palladium (Heroes Unlimited, Palladium Fantasy, Rifts, Robotech, Teenage Mutant Ninja Turtles, etc.)
 * Pros: Wide variety of material to support the system, much of it produced for the Rifts game.
 * Cons: System suffers from its lack of consistent central mechanics and significant Power Creep Power Seep. System creator Kevin Siembieda's stance against posting conversions to or from the system and (to a lesser degree) any original material for the system on the Internet is off-putting for some fans.


 * Prose Descriptive Qualities (Dead Inside, Monkey Ninja Pirate Robot, Truth & Justice, etc.)


 * Risus
 * Pros: Speedy character creation, easily-understandable rules. Also, free.
 * Cons: Lack of reasonable balance - for the most part, the character with the most dice will always win. Not well suited for serious campaigns, although it's doable.


 * White Wolf's Storyteller/Storytelling systems (Exalted, The World of Darkness, Scion, etc.)


 * Savage Worlds
 * Pros: Extra simple, with a slim rulebook that only costs $10.
 * Cons: Universal, but not generic--every Savage Worlds game plays like an action movie. Character customization is mostly limited to assigning ranks to skills.


 * Tri-Stat (BESM, Silver Age Sentinels, etc.)
 * Pros: It's free, and fairly easy to learn. It's animesque.
 * Cons: Not supported anymore, combat's slow. Easy to break.


 * True20
 * Pros: Based on a simplified d20 system, so most players will already have a grasp of the rules.
 * Cons: Powers are BROKEN. Uses a confusing and easily-overpowered damage track system instead of hit points, resulting in odd outcomes - for example, a non-combat-specialist one-shotting extremely powerful enemies because it couldn't see him.


 * Mutants and Masterminds
 * Pros: Has a wide range of powers and rules to customize said powers and/or the character itself. The basic books are so devoted to customization that the most of the different books add little new rules and deal mostly to adapt some concepts to a new fiction genre.
 * Cons: It is sold as super-hero game, but because of the nature of the super-hero genre it ends up being much more flexible. The GM must keep a eye to avoid game breaking.


 * A few Collectible Card Games use the concept of Universal Systems to bring together similarly-themed licenses under a single banner. This list includes the Universal Fighting System (which covers fighting games like Street Fighter and the Soul Series), the VS System (covering comic books like those of Marvel and DC) and the Crusade System (covering Anime, primarily Humongous Mecha series like Macross and Code Geass).
 * Then there's Hero Clix, which started with just Marvel and DC, but at this point encompasses a wide variety of franchises, including assorted video games such as Gears of War and Street Fighter. Add in Horror Clix (which I believe has compatible rules), and the Clix system will soon enough become as universal as a miniature system could possibly be.

Systems to add:
 * Active Exploits
 * EABA
 * GUMSHOE System
 * One Roll Engine
 * Rolemaster
 * Ubiquity System
 * Unisystem