Thursday, June 6, 2013

Of Hit-Dice, Multi-Classing, and Dual-Classing

This post is the result of work I am doing on my own retroclone-ish roleplaying game, but to make it at least semi-useful for others I'll follow the AD&D 1st edition rules instead.

Let's start with the basics. Your character earns experience points (xp) and after a certain number of xp have been collected, your character's level goes up. For a good chunk of your character's career, every new level means more hit-points, and you roll hit-dice (HD) for those. Both the kind of HD you use and the xp required to gain a level depend on your character's class.

So let's compare a fighter and a magic-user. Let's say each character has earned 100,000 xp which puts the fighter at level 7 and the magic-user at level 8. The fighter uses d10 while the magic-user uses d4 for their HD so (ignoring all other adjustments) we get these distributions for their hit-points: 38.5 (fighter) versus 20.0 (magic-user) on average. No surprises, all good.

Now let's consider an elven character who is a multi-classed fighter/magic-user instead. This character has to split xp evenly between classes, so 50,000 xp each for the fighter and magic-user classes, putting them both at level 6. The hit-points for a multi-classed character with two classes are generated by rolling both hit-dice but then dividing by two, leading to this distribution instead. (There's a small inaccuracy here because the rules specify rounding whereas the engine truncates by default; I tried to compensate for that by rolling all the dice at once instead of dividing each and every one by two.) The shocking truth is that our fighter/magic-user is really not much of a fighter at all: 23.75 hit-points (on average) is a lot closer to the single-class magic-user (20.0) than the single-class fighter (38.5). (In fact it's worse than rolling 7d6, which is what a single-class thief would have at 50,000 xp.)

But now compare this to a human character who starts out as a fighter but then dual-classes to magic-user. To make things roughly comparable to the multi-classing example, let's say we advance to level 6 as fighter for 35,000 xp. That leaves us 65,000 xp to pour into the magic-user class which gets us level 7. So we get 6d10 and 1d4 which leads to this distribution instead. So not only does a human dual-class character get an additional magic-user level, they also end up with 35.5 hit-points on average, very close to the single-class fighter with 38.5 hit-points on average.

So multi-classing sucks. And not just a little: It sucks big time.
Also dual-classing rules. And not just a little: It rules hard core.

Now let's do something really weird: Let's pretend we had the "unified level progression" mechanic from 3rd edition but let's pick the most expensive 1st edition progression for it. (We can't use the progression from 3rd edition "as is" because they lowered the cost for gaining a level a lot compared to 1st edition. Using the most expensive progression from 1st edition means we'll be conservative.)

Turns out that with 100,000 xp all classes in the 1st edition Player's Handbook reach at least level 7, but the Paladin progression cuts it closest with 95,000 xp required. (The monk progression requires 98,000 xp but that's for 8 HD since monks start with 2 HD at level 1.)

So if we translate forward into 3rd edition again we have at most 7 levels to play with: We could build a fighter/magic-user with levels 1/6, 2/5, 3/4, 4/3, 5/2, or 6/1. Let's pick 3/4 with the magic-user level higher than the fighter level to stay close to our previous dual-class example. All that futzing around gets us this distribution which is perhaps the most shocking one so far: 

It's absolutely perfect!

In terms of averages it comes in at 26.5 which is significantly higher than the 20.0 a single-class magic-user gets. It's of course also significantly lower than the 38.5 a single-class fighter gets. This is in contrast to multi-classing with 23.75 which is much too close to a single-class magic-user and dual-classing with 35.5 which is much too close to a single-class fighter.

Like many who consider themselves "old school" I didn't expect to find something great in the 3rd edition design. But it's clearly the case that unified level progression and the revised multi/dual-classing mechanic achieve the kind of balance I would expect from mixing multiple classes. Neither of the 1st edition approaches even comes close.

Which is why my own retroclone-ish roleplaying game works like 3rd edition in this regard. Stealing the best ideas from all editions, that's my kind of old school.


  1. The 3e-inspired 3/4 ftr/wiz will be significantly worse at wizarding than the 6/7 ADD multiclass wizard. Even worse if he decides to try and keep up with the Fighter's hit points.

    One thing I've considered is combining the dual class rules is to keep two hit point totals, one for each class, and use the higher of the two. That way he will hang out with his 6th level fighter hit points for awhile and it also means that a fighter that dual classes into a MU won't always be better than an MU that dual classes into a fighter.

  2. I agree with Hedgehobbit. The 3/4 character will woefully under perform next to their 7th level companions. While I realize that OSR games handle level disparities better than 3.X or 4E does, that doesn't mean that it won't be keenly felt. The problem will also remain constant throughout their career. Unlike the Dual class character who will eventually get within a level or 2 of his companions, this character will always remain weaker.

    I don't really think that hit points should be the only rubric used when deciding how well the multi-class system worked in the older editions. The Fighter/Mage wasn't meant to be as good as a single class mage in straight up combat, but fighting was meant to be a tool in his toolbox if need be.

    That is not to say that I don't agree with the overall thrust of your post, which is that design innovations shouldn't be ignore simply because they come from later editions. I think 3E and 4E did tons of things right that retroclones could (and in some cases do) benefit from.

  3. It seems to me that the crux of the problem is whether you want to consider multi-classing a "minor inconvenience" or a "major commitment" on part of the character.

    Under the 1e rules they'll lag about one level behind in terms of class abilities, but they'll also be very close to the weaker class in terms of hit-points. For the most part that's an inconvenience, you just play them as a member of the weaker class with a knack for the occasional "exotic" activity.

    Under the bastardized 3e rules they'll be about half as powerful as their single-classed compatriots in *every* regard. That's what I'd consider an appropriate commitment, but your mileage may obviously vary.

    It has always bothered me that multi-classed characters get almost all the fun of single-classed characters, so for me the pseudo-3e approach seems more appropriate.

    I think there's also a side benefit: Given the pseudo-3e approach, demi-humans become a tad bit less attractive. I've always encouraged my players to go for humans anyway, but here's another reason, even before most level-limits come into play, that pushes them away from playing "humans in funny hats" as it were.

    Note that I didn't say anything else about dual-classing here. As far as I am concerned, that mechanic is simply too over-powered to he saved. True, you have the (possibly brief) period of time during which the newly dual-classed character just cowers in the middle of the party with everyone else protecting them. But once they are through that barrier they are the undisputed kings of whatever second class they picked. I enjoyed that in Baldur's Gate, but I would not enjoy it outside of a CRPG.

  4. How would you resolve Saves and To Hit? In 3rd ed they are additive, so taking parts of classes and adding them together makes just end up with a lesser number (for to hits) or a greater number (some saves) than otherwise. But in old school, that doesn't really work. And leaving a 10th level character with 5th level saves? That's not a serious commitment, that's approaching an unplayable party liability. That character will never escape from hiding in the center of the party.

    Obviously YMMV, but few of my players in ACKS are willing to play Elven Spellswords or any of the high cost 'multi-class' classes. The thought of making it through 1st level needing 4K exp is just too daunting.

    As to humans and non-human race choices, it's easy enough to give humans some sort of 'racial bonus' as 3rd ed and 4E did. That makes the most sense. Fast advancement is the one I see most often (+10 or 20% xp). But depending on the system, others might present themselves (I allow in ACKS for a human character to have a bonus proficiency that can be taken from any class list at level one, so long as it makes some kind of sense for the character class).

  5. In my own hack of a pseudo-retro-clone saving throws are based on *character* level while attack ability is based on *class* level (which I call "rank" to be able to abbreviate things as L and R unambiguously).

    So if you're a fighter/wizard 3/4 you save as a level 7 character. That seems fair since saving throws should be proportional to the total experience gained (and therefore the time committed to the character by the player) and not proportional to their abilities in any particular class. However a fighter/wizard 3/4 would attack as a fighter 3 (+3 attack bonus from class) and not as a wizard 4 (+1 attack bonus from class). Again that seems reasonable since the character can otherwise freely combine the abilities of a fighter and a wizard, a more versatile thing than a "pure" fighter 7 or wizard 7.

    As I said, that's my little system. I never tried to "apply" this to AD&D 1e directly, but I think I'd largely do it the same way.

    You mention that few people in your campaign want to play elven "spellswords" and from my perspective that's perfect; from yours it may not be. :-/

    The experience bonus for humans can work, but a penalty for demi-humans could as well. I mean instead of tracking separate experience totals for two classes you could just say "use the more expensive class and then add +30% for two classes or +50% for three classes" and run with that. Of course the inconsistent level advancement between classes (magic-users for example, see for some details) makes that complicated in AD&D 1e. But it could work.

    Please don't think that I am trying to tell you to change your game. Use whatever you think is best! I am just "thinking out loud" in these posts to see what kind of feedback I get. And I very much appreciate you taking the time to discuss this with me!