Ask The Readers: Do RPGs necessarily need a unified core mechanic?

toolkit Back in the early days of roleplaying games there were often different roll mechanics for the various aspects of the game. In some games you had to roll with a d20 and get high results to hit but roll low with percentile dice to succeed in your skills. Often one game used various ways to resolve tasks. Each “mini game” had its own mechanics.

Nowadays roleplaying games often have a unified core mechanic. Think of the core mechanic of the d20 System for example:

Whenever you attempt an action that has some chance of failure, you roll a twenty-sided die (d20). To determine if your character succeeds at a task you do this:

  • Roll a d20.
  • Add any relevant modifiers.
  • Compare the result to a target number.

If the result equals or exceeds the target number, your character succeeds. If the result is lower than the target number, you fail.

While it’s pretty elegant to use the same core mechanic for all of a game’s subsystems, is it really necessary? Or wouldn’t it sometimes more fun to replace the one core mechanic by a whole toolkit full of different mechanics, each designed with a game’s subsystem in mind? What do you guys think about this subject? As always every comment is highly appreciated!

28 thoughts on “Ask The Readers: Do RPGs necessarily need a unified core mechanic?”

  1. I think a unified core mechanic is important. If you want to build a complex rules system, you can build different subsystems on top of the core mechanic (I’m thinking of Burning Wheel as an example here), but if the same core isn’t used throughout, the whole thing will feel haphazard.

  2. I don’t think a unified core mechanic is strictly necessary, but I think it’s important for a game’s mechanics to seem intuitive and to fit well with each other. There have been many games filled with disparate systems which simply seem disjointed and chaotic, which can be a major barrier to play.

    1. I fully agree. But I remember games where you rolled a d20 for attack rolls and d% for skill checks and this worked pretty well, while on the other hand it’s sometimes not so great when you shoehorn everything into one unified mechanic.
      But I agree that in most cases a unified core mechanic is the way to go, I just believe there might be cases where using different mechanics for different subsystems may be interesting.

  3. No.

    The reason is that most* mechanics aren’t that difficult to learn. Those that are large tend to be compartmentalised – you don’t need all the mechanics at the same time. You don’t need to know about mortgages in Monopoly until you’ve sold yourself into a hole.

    I’d also add that the role of mechanics is to provide the players with tactical choices. Players get great joy from manipulating the system to work for their needs. A single core mechanic means that all systems will have the same tactical choices and will inevitably feel the same.

    D&D will always be the core RPG that most people will go to (pity it’s not free) so that will become the de facto standard. That’s ok too – when a player team tire of D&D then they can move onto another game. Having new rules to learn is a barrier of sorts but then it can be a fun barrier. If it’s too much of a barrier then they’ll probably do what everyone else does and find a simpler system or just hack homebrew changes into D&D.

    * With a few exceptions – I’ve seen a couple that have had me scratching my head.

  4. I think you need a really, really good reason to have multiple systems rather than a core mechanic. If your principal mechanic doesn’t capture an essential part of the game, you need to rewrite your principal mechanic so that it does (or can do, with a subsystem on top of it). For anything that’s not an essential part of the game, it’s probably not worth the additional rules bulk to have a separate rules system.

    1. I agree.

      I’d answer a conditional “no” to the question of the necessity of a core mechanic. The condition is a strong one, however: the game must be based on simple ideas to be fun, otherwise, you’re always playing Shadowrun. . . oops, I mean, you’re constantly referencing the rules.

      It seems to me that an easy way to achieve simplicity is to offer a core mechanic. Is it the only way? Probably not, but it seems rational that, the easier a system gets, the closer to a core mechanic it grows.

  5. I had a longer reply, but it got eaten by the blog software (it doesn’t retain the text if you have to “go back” because you forgot to login).

    IMO, minimalism is the best approach. “Do what is necessary, and nothing more”. If you need to model something, have a VERY good reason for why it doesn’t fit an existing mechanic. If you can’t come up with a good reason, then re-use one of the existing mechanics. If you’re writing a simulationist game, you can probably come up with lots of good reasons for individual mechanics. If you’re writing a story-oriented games, then probably the opposite is true (because the nuances of novel mechanics aren’t as important to the _story_).

    And, keep in mind, there are quite a few games with minimal mechanics out there, and that have been successful with it. Storyteller. FASERIP (the 1980′s version of Marvel). Heck, even Fudge.

  6. I’m running a survey right now to try and get solid data on what players at least say they want about this and other topics. I’ll release the results publicly once the survey is done. So hopefully this will be helpful to the whole community.

    So far the resounding opinion is yes.

    However that does not mean it can’t be done, it probably means that in those players opinion it wasn’t done well.

  7. It’s not necessary. People play games today, that don’t feature a unified core mechanic.

    I play AD&D, S&W, OD&D & LL. I prefer a game I can easily hack & houserule. And I don’t care for games that have a ton of rules, anyway.

    1. I can’t tell which side you’re advocating here..
      “it’s not necessary [to have a unified core mechanic]”
      vs
      “I don’t care for games that have a ton of rules, anyway”

      Those seem to be in stark contrast… as unified core mechanics tend to reduce the overall bulk of the rules (not always, but tend to).

      I also find it funny that you put the “I don’t care for games that have a ton of rules” immediately after “I play AD&D”.

    1. I agree. I can recall the early days of D&D when new players would come to the table and be confused with which dice they used when.

      At the time I may have considered it quaint how they didn’t know as much as the rest of us.

      These days I see that issue for what it really was (is): a barrier to them embracing the fun.

      Elimination of such barriers should be a priority if we really want to mainstream gaming.

  8. Core mechanics make teaching a game to new players easier. Also, as gamers get older, the trend is going to be for more games that have streamlined or intuitive rules as opposed to complex heavy systems with subsystems.

    I personally don’t mind have a myriad of subsystems. It gives the chance to use other dice. If I wanted to play True 20 with just the d20, I can do so, but I also like every once in a while to roll d20 to hit, roll 1d12 for 2d6 for a morale check, roll 1d100 for skill checks or class ability checks, and roll lots of whatever for damage. But that’s me.

  9. I think there should definitely be a core mechanic but I’m not against there being a secondary mechanic. I do think the secondary mechanic should be different for a reason however. Like if you were going to re-do Wraith: The Oblivion, having a completely separate mechanic for handling Shadow would be cool to emphasize how different and removed from you the shadow is.

  10. I like having a core mechanic, but is it necessary? No.

    AD&D is about as far from having a unified core mechanic as a game can get, and it still managed to do OK.

  11. A core mechanic is training wheels. Harmful if not eventually cast off.

    Not having one teaches the DM to homebrew by forcing him to come up with rulings when he inevitably encounters situations the rules don’t cover.

    I’d even go so far as to say that core mechanics subtly undermine DM authority in the long term.

  12. Interesting topic that I also need to cover in my documentary thesis. Unified mechanics are a good starting point. They are easy to learn, which is good for financially minded devs. If your system is easy to get into, people are more likely to play (and buy) the game. Who cares if the game becomes so uniformly designed that it’ll bore the hell out of players after short time.

    People strive for mastery. At least a significant amount of players want to get the most out of their characters. While I am no supporter of unnecessarily complicated rules, you need to bring fresh crunch to the table to keep things interesting. Taking setting/fantasia aside for a minute, mechanics enhance a player’s opportunities to affect the game.

    I am trying to do both with Michtim RPG. Easy (unified) basic actions, but a plethora of special addon rules for individual character classes. Only the GM and relevant player have to know these specialty subsystems, or Mini-Games (nice point, Stargazer)!

    1. “you need to bring fresh crunch to the table to keep things interesting”.

      That’s only true for a certain type of player, and it’s a cheap style of game design. It’s the D&D “splat book” philosophy of tossing a shiny thing at the customers every so often, just to keep their attention… even though the amount of substance in each such product is rather low.

      It also assumes a sort of video game “power up” mentality among the players: if they don’t regularly get some form of “power up” then they’ll get bored and move on.

      It’s true that these two techniques will work, marketing wise, for a game. I’m just saying: they’re the cheap “low substance, flood the market” path of game design. Another way to look at it is the heroin or crack model of marketing — it works, but it’s not really something to be proud of.

      To look at a different path, there’s Hero. A few main core mechanics (really, the core mechanics of Hero are rather small), and yet they are so rich and diverse in their application that “striving for mastery” is an actual intellectual challenge. But it’s something you actually master, not just the process of collecting shiny things every month. The supporting products are actually talking about how to apply those mechanics to new situations, and at times have been catalogs of real world history and artifacts.

      A similar case can be made for GURPS (whose supplementary products have often been bought by GM’s from other games, just for the rich setting material).

      Neither of them are really offering you “fresh new crunch” (like a D&D splat book) as much as they’re offering new ways to see/apply the existing crunch you’re already working at mastering. Instead, they’re focused on substance over shiny. Instead of creating new novel mechanics that needlessly complicate the game (but feed your addiction), they offer you new richness to the existing core mechanics.

      And that model requires a rich, flexible, but discrete, set of core mechanics.

      1. I do not entice ripping players off by forcing them to buy ‘rule updates’. I don’t like that approach myself. I know splat books only from the World of Darkness game line, but there you could also see the tendency to present new game mechanics that always offered superior (unbalanced) game material.

        I want to empower players to co-create new material. To go creative with themes. But I cannot understand what you consider to be ‘cheap game design’ in that case.

        If you like tons of setting material that is totally okay. As you’ve already hinted at, there are many different player types. I was talking crunch, not fluff. This does not have to be shiny new things. Maybe we have a misunderstanding: I was not even talking about supplementary books, but rather the way non-core rules can enhance the game by being sort of mini-gamish.

        But I’m curious if that was, what you had a problem with.

  13. I do not believe that you need to have a unified mechanic system. I do believe that the mechanics you use have to make sense.

    Unfortunately, it’s been a long time since I saw a game that had diverse mechanical checks. Deadlands is the only one that comes to mind, and that’s only due to the occasional use of the deck of cards. D&D exists, of course, but I’m hard pressed to think of a more modern game that does it that I’ve played.

  14. I do not entice ripping players off by forcing them to buy ‘rule updates’. I don’t like that approach myself. I know splat books only from the World of Darkness game line, but there you could also see the tendency to present new game mechanics that always offered superior (unbalanced) game material.

    I want to empower players to co-create new material. To go creative with themes. But I cannot understand what you consider to be ‘cheap game design’ in that case.

    If you like tons of setting material that is totally okay. As you’ve already hinted at, there are many different player types. I was talking crunch, not fluff. This does not have to be shiny new things. Maybe we have a misunderstanding: I was not even talking about supplementary books, but rather the way non-core rules can enhance the game by being sort of mini-gamish.

    :) But I’m curious if that was, what you had a problem with.

  15. I enjoyed reading the comments on this post. Sharkbone episode 75 features a good conversation about core vs. multiple resolution mechanics which I highly recommend. My 2¢ is that a strong central mechanic is necessary to establish the game identity while specific sub-systems allow for better highlighting of a games specialized perspective.

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