Friday, August 27, 2010

Fun with Fungibility

So, a fungible[1] resource is one that can be easily replaced with another resource of the same kind. If you have a cup of water, and pour it into a bucket of water, then scoop out a cup, you're pretty much where you started. Ditto something like a twenty dollar bill or a couple volts of electricity. There are all sorts of interesting economic implications to resources like this (in contrast to distinct one) but they're also useful to think about in game terms.

A lot of the numeric values you see on a character sheet are fungible. Things like attack bonus or hit points are made up of an aggregate of other numbers (Stat bonuses, equipment bonuses, level and so on) and while those elements may matter a great deal when you're building the character they all run together once the dice hit the table. If you hit that enemy, there's nothing in the flat bonus that tells you whether you hit him because you're strong, because your weapon is particularly accurate or because of the advantage you got from flanking the guy.

This means that, in practice, bonuses are interchangeable. There are few places this is more evident than in 4e, where different stats often end up being used for the same thing (such as making attack rolls). here are a lot of benefits to this approach. It's incredibly flexible. Adding new elements requires only that they fit into the current economy, so swapping out parts is easy. It all comes out in the wash when it comes time to calculate the final total. It also makes (as 4e illustrates) reskinning of elements entirely trivial.

But all of this gets interesting when you contrast it with elements of the game which are very clearly not fungible. To stick with the D&D example, if you miss an attack, but then use an ability that grants you a reroll and hit, your sense is that you hit because of the reroll. If the power had given you an extra bonus before you rolled, you probably would not think "I hit because of this power" because it's just one of many factors in your total bonus, but since the reroll is a change of type (from a fungible resource to a distinct one[2]) then that's where the cool thing happened.

You get similar reactions when you look at the results of attacks. More damage is nice, but since damage is fungible, it's not particularly cool if your damage came from hurling daggers of pure ice and my damage came from hitting the guy with a very big stick. Things get more interesting when there is differentiation in the form of non-fungible elements like extra effects. If my ice daggers slow a guy down and your big stick knocks him back then our attacks now feel different in a way that pure damage didn't allow.

This is an incredibly important point to understand when you start thinking about the role of color in an RPG. Some systems are almost entirely fungible, with the understanding that all distinctions in effect are part of the color. Other games have very limited fungible elements and lots and lots of unique elements. But it's not a simple split. On one level, everything in Hero is fungible - the underlying idea of what a point is worth is the currency everything can be broken down into, but the complexity in doing so creates a barrier to treating it as truly liquid.[3] And more, there's no 'right' way to handle it. More or less fungibility does not make a system better or worse.

But it can make a system more or less in keeping with your vision, and suggest where you need to put in levers. To use the previous combat example, you need to decide if pure damage is enough to handle things in your system or if you need points of distinction. You can decide if general bonuses get you what you want, or if you need make things a little more specific.[4]

Again, do with it what you will, but if you stop and look at a part of your system and ask what this looks like if you swap in something else, and if that's what you want to see. 4e shows us how useful it can be, but also demonstrates that doing it well requires really committing to the idea. If you're not willing to go that far, then make sure you're getting what you're hoping to find.

1 - I am using this word in a way that will make strict economists cry, but it's a useful concept, so if you are enough of an economist to get where I'm taking artistic license, please accept it as that.

2 - yeah, theoretically rerolls could be fungible too, but at least in 4e. In fact, by standardizing things, most of the element sin 4e are fungible - a "stunned" status works the same whether it's from a blow to the head or from a painting of the 8th dimension. This is intentional, since it allows for easy swapping of color without disrupting mechanics. That said, rerolls are player-controlled and serial, so they're different enough to be a useful example.

3 - And this one's for the nerds - Liquidity is NOT fungibility. Liquidity is the ability to turn something into something's intrinsic value into actual value. A golden statue may be worth a lot, but it's hard to spend, so it's illiquid. Sell it for cash ('liquidate' it) and now you've got some money to burn, but while that money may be fungible, that doesn't mean the statue itself is. Fungible and Liquid often get conflated if only because liquidating something usually means exchanging it for a fungible asset (since they're more easily exchanged).

4 - The Ironclaw/Jadeclaw system does something interesting with this. You roll several dice when you act, one for stat, one for skill and so on, with each bonus expressed as a die. You pick the high roll and based on which die it is, you know why you succeeded (and can infer color about other things from the roll too). Cortex could also support this too, but it does require some curious bookkeeping when rolling more than one die of the same type - you'd need different color dice and some clear way of distinguishing them. Kind of a pain, but very neat in theory.


  1. So, in FATE, are temporary Aspects fungible? I mean, pretty much every Aspect has exactly the same mechanics supporting it. But, the definition of the Aspect determines when it can be tagged.

    If I spray a tiled floor with gasoline, I can give it the temporary Aspect "Slippery." If I the drop a match on it, I can give it the temporary Aspect "On fire." Adding the Aspects uses the same process, as does tagging them. And, tagging them for a bonus works the same way, giving you +2.

    But, they are actually different triggers for when you can tag them. And, they give you very different effects when you tag to do a declaration.

    I'm not sure I understand yet what "fungibility" means when talking about game mechanics. I see where you want to go with it, I think. But I can't really understand how you are drawing the lines to get us there.

  2. Yes, but not exactly in the way you describe. And regular aspects have the same potential problem (at least potentially).

    If the aspects must be triggered differently (that is, I would need to take different actions to use them) then they're not really fungible. For clearly delineated aspects like "Slippery" and "On Fire" there's not much chance of them being interchanged.

    BUT, in terms of pure bonus, aspects are fungible, in that they're all just different ways to get a +2 bonus. If it doesn't matter which aspect you use, it becomes easy to gravitate towards using a handful of "general purpose" aspects like smart, fast or lucky. Aspects which can be used in almost any situation are absolutely fungible.

    And this is, by the way, a real weakness to the system. Yes, we call those aspects out as boring, but the reality is that it's very common for a player to develop a handful of "crutch" aspects, and that can get very hard to deal with.

    To illustrate the broader idea a big further, let's look at Risus. You and I might both have characters who are "Warrior 3d" who are COMPLETELY different. Plate vs. leather. Huge polearm vs. nasty knife. Hardcore tactics vs. free-for-all. Those differences don't come up in the mechanics - since they just boil down to the mechanical expression of "Warrior 3d". That is both a bug and a feature - it's flexible and fast, but it might also be ultimately unsatisfying.

  3. Although it would take longer, you could roll all of the dice in a Cortex Plus roll individually and in that way keep track of the two highest dice. It would certainly be cool to think of your success being because of the Crowbar and your Strength dice as opposed to your Confidence and your Hitter dice. Or whatever.

  4. Great post! I'd thought through the probability math of rerolls, but hadn't spent as much time on the psychological difference at the table.

    Having played a lot of 4e over the past few years, one of my problems is that so much of it is fungible. The differences between how different characters put status effects on monsters isn't nearly as great as I'd like it to be. And the distinction between power sources isn't as great as I'd like. (For example, in earlier editions, silencing a wizard, cornering him, or otherwise neutralizing his arcane powers were somewhat viable tactics. In 4e, it is just a power source, and they've been pretty careful to avoid putting in any anti-specific power source effects).

    With regard to aspects, I touched on some of this in a recent post.

    On one level, yes, aspects are just a +2 bonus with the triggering conditions defined by player and GM agreement. The way to get out of that trap is to really weave the aspects that are being used into the story. Yeah, on one level all I did was add 2 more stress to damage, but on another level, describing how I did so is what makes it storytelling, and not just a mathematical exercise.

    Back when I was regularly playing SOTC, I pushed this with my PC. One of my aspects as "Down to Our Last Chance". On one level, the idea was that my character was a 'closer' -- when the cards were down and at their most desperate, he would come through. But the flip side of that was that if I tagged that aspect, it really was the last chance to deal with the problem in the way we were confronting it. No matter what, when I tagged that aspect, the situation must change afterwards. It didn't end scenes as much as it changed the nature of the scene. (e.g. we finish off the ape minions, but now the village is on fire).

    That's something of an extreme example of the concept -- a tag shouldn't make huge changes or derail the GM's story direction. And realistically, I always avoided tagging that aspect until it was appropriate for the story.

    I guess I'd say that aspects work really well when everyone at the table is trying to make them work well. When they become just a mechanical bonus, they really aren't very different than "I get +2 for flanking". As a player, I always try to make sure I'm tagging the right aspect for the situation, and not just grabbing whatever aspect I can justify. To channel Toy Story, we're not flying, we're falling...with STYLE! If the adventure is leading up to my former master's deathtrap, I'm definitely going to tag "Apprentice to the Warlock" and make that confrontation, and not just tag "Slippery".

    Names have power, of course. Give an aspect a better name, and it tends to be cooler when it actually gets used.

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  8. Sorry for the extra posts. I was getting an error back when I made the post, and I assumed the error meant that posts were not actually showing up.

  9. See, when people ask me why I like stunts in my Fate, I think this is part of why. Because they trigger under specific circumstances and their benefit is spent in a specific way, they're less fungible (if I understand the idea), and thus they're where some of the "pop" can happen in play.

    Your superpower aspect notion in the cold war game does much the same thing, in that it makes the aspect's scope of operation and effect different and thus (I believe) less fungible. There are some fiats I can do with mine that I just can't do with the others.

    (That said, the fact that even vanilla aspects can and often do come into play AFTER a roll, and you can see the effect each aspect has on getting the roll from failure to success, they certainly bring some potential to be the Thing Pointed At As The Reason Why We Won.)

    I don't know that I'd ever have used the term "fungible" to describe the thing that I'm trying to play counterpoint to with things like stunts and so forth -- I'd probably just call it "slipperiness" or "fluidity" -- but it's a good perspective to bring to the party. And that counterpoint I'm looking for, the "infungibility" is what I might just mean when I say I'm looking for something in a design to give me "traction."

  10. We had great success with going back and forth between the villain and hero, turning success to failure to success, as each tagged aspects on a single roll. It lasted until someone gave in/couldn't spend the fate points/couldn't justify an appropriate aspect. It burns fate points like crazy, but it really took the most important scenes and extended out a single action into a dramatic conflict.

    Smallville is worth a look for a more holistic back-and-forth conflict resolution mechanic. I'm finding a ton of great ideas to mine from that game.


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