Monday, July 12, 2010

Swimming in JAGS

I periodically get emailed questions about the JAGS rules. I do my best to answer them but I know why one of the Champion Designers (I think it was Aaron Allston) wore a shirt that said "I am not a Champions guru." It turns out that not only is my head full of JAGS rules, it's full of several editions of JAGS rules including the copy-shop bound early versions that you'll never see (I don't think I even have any anymore). It's full of various corrections and revisions of the current rules. It's full of stuff I wanted to put in and didn't. It's full of discussions and arguments I've had with the other people who've helped me with it.

When W.S. asked me if there were swimming rules my only thought was "search the PDF. It's what I'd have to do."

Apparently it turns up NOTHING. So let's take a look.

You Complete The Game
The 1st edition of Gamma World had GM's notes that explained that the Game Master "completed" the game. I love this idea. They meant that the act of making an actual scenario was, in a way, "completing" the game--sort of--even if just a little--like making a new set of rules. Of course I don't think the original Gamma World had any rules for swimming either and that didn't mean no mutant could ever swim. If there needed to be rules the GM would be expected to "complete the game" and come up with some.

Here's What I Did (and Would Expect You To Do)
While I was watching Eclipse with my wife this weekend--about the third time or more that the werewolf with the great abs got stalkerfific with the fang-banging emo-girl I started thinking about swimming in JAGS. How would I do it? the question breaks down into a few parts:

  1. What are the (general) rules for being submerged? What are things like movement rates when swimming and things like that?
  2. What does a character need to have in order to swim?
  3. What differentiates a dog-paddling swimmer from Michael Phelps?
In order to figure this out--and these are not "official rules"--I used the universal ubiquitous data-library: Google. I also just applied some general thinking to get rules for the first question.

Rules For Being Submerged/Swimming
Clearly being in the water is hard for people who don't know what they're doing. Plus, they can drown. Movement rates will be slowed, people are easier to hit, and you can suffocate. Also: water would protect you from incoming strikes and stuff.

  • Unless you are an aquatic creature or have some special trait, you lose your AGI bonus in the water.
  • Unless you have some special traits you must spend 5 REA per Round "swimming" or sink. You can hold position (assuming you can swim) or keep on moving or start moving (which will cost you 8) but unless you want to sink, you pay 5 REA at the start of the Round or down you go.
  • Water will make most strikes inefficient. Let's say it confers a -6 Damage Modifier to all attacks (mostly submerged characters get Coverage of 4 that will either result in a miss (simple) or a -6 DM).
  • Knives and spears and other "aquatic weapons" don't suffer this modifier or any modifier at all.
  • If you start drowning you probably fight at -4 unless you make a WIL roll by 4 or more each Round. Skill levels can negate some of this. You can hold your breath for CON Rounds if doing very little but combat is taxing: if you can't breathe water you will start drowning if completely submerged on the 2nd round of combat (assuming you don't spend 5 REA to keep your head above water).
  • A successful grapple can hold someone under water.
  • After your time is up, at the end of the next Round you are unconscious and dying.
How Fast Do You Move?
I asked Google "How Fast Do People Swim" and got a link that said most people at a leisurely pace go .8km per hour. Google calculator (like, the best thing I've ever seen) says that's .24 yards per second or .75 yards per move action. Let's kick that up: an untrained person swims at 1 yard per second for Walking Endurance. 

This is a great link because it goes further to say that if you are determined--but not an athlete--you go at about 2 miles per hour or, doing the JAGS math, 3 yards per movement action. That's Sprinting Endurance.

Finally, it goes to professional athletes. The numbers come out to a top speed of about 6 yards per second as a top contender: being highly trained about doubles your speed.

How Do You Purchase It?
This is a great question. Clearly the generic Sports Skill could be Professional Swimming. So, hey, that way? Well, no--that's not the whole story. My daughter can swim and she sure doesn't have 2 CP invested in swimming (even at L1). I can swim better and I don't have points invested either. While there is a Swimming Skill (in theory) you don't need it to swim a little: that doesn't make sense.

Why not? Well, the obvious answer is "most people can swim with a lot less training than it takes to, say, learn Karate." Even more to the point though: if the game is (somehow) about professional swimmers (I once ran a game where a PC was on a high school volleyball team) then you want the skill to differentiate skill levels in competition. It's fine for that. If a PC wants to be a really strong expert swimmer then, okay, invest the points in the Sports Skill--that's what it's there for--but not only does a strong investment fail the reality check, it fails the good game design check. Forcing anyone who might go near water to spend 2-3 CP or risk death is just a bad call ... and, really, vanishingly few characters in fiction are distinguished "by the fact that they can swim."

So How DO You Purchase It?
Well, a look at the all-knowing Wikipedia under Swimming suggests that in the UK kids who can't swim 25 meters get about 10 hours of remedial training. That isn't much in the grand scheme of things (further pointing out that it shouldn't be a skill for most people). Let's go to the book and see if there's an example.

I cite the limitation "Lousy Driver" (pg 83, I looked it up). In game-worlds where there is an assumption of competence then the lack of the skill becomes a negative point Trait (a defect). So, say, for modern day it's -1 for Can't Swim. Something like that.

In game worlds where there is no presumption then it could be a skill (but probably not an Expensive one unless you are a sport swimmer). So say it's a Normal-cost Skill for medieval Europe and an exotic one. A Level 1 ability in it would give basic survival level swimming. Higher levels would make you a little faster, give some resistance to negatives, and so on.

Alternatively you could just make it a 1 CP Trait "Knows How To Swim" and call it a day.

What About The Sport Skill?
A look at a couple of competitive swimming pages show that there are some special skills around the start, the flip-turn. Without further research, I would assume that the skill there gives advantages measured in seconds or less to the better practitioner. There's also military swimming mentioned which (I assume) trains for holding breath, intel-gathering, and setting up explosives underwater. Maybe you wire them to the trained dolphin or something ... I don't know.

Anyway, all of this is handled by the Sport Skill. In a competition the characters will be having a Drama Roll session to see who can generate the most SPs. Having a roll requires the skill (if you just had the Normal Skill you probably couldn't get more than 1SP for making it--probably at a -3).

So that's still an option if you want to play Michael Phelps.

-Marco (I'll answer his other question later)


  1. Just a couple of comments about this, one about design philosophy, one about swimming :)

    Philosophy: I don't expect a game to cover every possible contingency when it comes to doing things, but there's a concept I have called "assumed scope". "Assumed scope" says that a given set of game rules is targeted at a certain scope of coverage. This has to do with what the game's about, but it also has to do with crunch and depth. JAGS is a universal system, so its got a wide coverage, so it can't entirely get off the hook on anything, but it also can't be reasonably expected to cover everything, either. On the other hand, its a fairly high crunch and medium depth game, so it reasonably has to be expected to cover fairly common general cases. While not trying to bust your chops here, falling into and/or otherwise having to deal with water is, I think, at least as common as things like climbing, so I think its one of the things one could reasonably have expected to find in JAGS. Its not a rules light game, you know. :)

    Swimming: I agree that probably most people should be able to swim after a fashion; defaulting to an attribute (say, Agility) and an unskilled use is probably a fair cop; the "Cannot Swim" issue is only likely to be a case for people who reach adulthood completely unexposed to it, and thus, immediately panic.
    That said, Sport strikes me as perhaps an odd place to put the full skilled version, even though it clearly is used as a sport; among other things the kind of uses that will be important to a typical PC are parts learned more commonly by various sorts of professionals (usually divers, but the swimming ability doesn't go away because you lack a rig). Of course there's no functional difference between a Profession and a Sport if you base them on the same attribute.

    Thanks for the post.

  2. Oh yeah, let me be clear: the game 'ought' to cover swimming (and zero-g combat). If it doesn't that's not good.

    What I meant by "Expect You" to do is this: if the game does fail in some place then I wouldn't (as a default expectation) assume play would _stop_. My assumption would be that play pauses, the GM complains that the rule-book is lacking--and then then makes a call.

    My default assumption would be that 20 minutes of web-searching and some guess-work could give decent info on swimming. The actual "rules" I came up with are not tested or well examined--but I think they would work okay in a game where balance of swimming wasn't crucial.

    As to the 'Sport' element: The "sport" skill would probably cover the fastest-possible Michael Phelps character. If the character is a professional diver, however, a general occupational skill could be used (which would cover tanks, underwater safety, and stuff like that).

    The difference would be seen in two places:

    1. A character who is the world's fastest swimmer or otherwise makes a living (or a fortune) doing that. That's likely to be an Expensive skill or, perhaps, a Trait (like Fast Runner) that has a couple of levels of it so you can distinguish from the fast to not-so-fast.

    2. If the character is simply good underwater and knows how to use the gear and can reach a good but average clip for a strong swimmer (in depth rules could modify the top speed by the character's physical attributes) then, yeah, that is probably a Normal-cost professional skill.

    I also want to point out that this is the sort of conversation I would expect to have with a player so getting a complete set of rules right the first time out isn't as important as refining the thinking over a discussion.


  3. Sure. I'm sure if it'd come up in play, I'd faked something; I'm probably a low roll Professional level swimmer myself in JAGS terms, so I have some idea what it should work like. It just startled me because I've gotten so used to finding swimming rules in more complete games, and JAGS otherwise covered the normal ground. Then I got caught up in the question of what category of skill it would land in, and off I went.