How much of an impact do multiclass XP penalties make?

[heavyfuel]

Please let's not argue whether or not this rule should be applied to games, just its impact

The questions is pretty straight forward. How behind will characters with multiclass penalty be from the rest of the party level-wise?

Eg: If a character has 20% xp penalty, starting at lv 4, by the time the rest of the party is lv 9. At what level will he be?

What if he has 40% penalty?

[Jay R]

If he has a 20% penalty at level 4, that means he is at 6,000 xp at the same time everyone else is. When the rest reach level 9, they are at 45,000 xp. So while they got the additional 39,000, he got 80% (39,000) = 31,200 added to his original 6,000, for a total of 37,200. So he’s at level 8. He needs an additional 7,800, so he needs to earn 9,750 xps. He will reach 9th level right before everybody else reaches 10th.

At a 40% penalty starting at level 4, be at 29,400 when the others are at 9th level, so he'd be at level 7.

[heavyfuel]

If he has a 20% penalty at level 4, that means he is at 6,000 xp at the same time everyone else is. When the rest reach level 9, they are at 45,000 xp. So while they got the additional 39,000, he got 80% (39,000) = 31,200 added to his original 6,000, for a total of 37,200. So he’s at level 8. He needs an additional 7,800, so he needs to earn 9,750 xps. He will reach 9th level right before everybody else reaches 10th.

At a 40% penalty starting at level 4, be at 29,400 when the others are at 9th level, so he'd be at level 7.

Unfortunately, a direct calculation such as that doesn't work for this. By the time the party gets a level difference, the member left behind will earn more XP from being a level below them ("xp is a river" and all that)

[thoroughlyS]

If he has a 20% penalty at level 4, that means he is at 6,000 xp at the same time everyone else is. When the rest reach level 9, they are at 45,000 xp. So while they got the additional 39,000, he got 80% (39,000) = 31,200 added to his original 6,000, for a total of 37,200. So he’s at level 8. He needs an additional 7,800, so he needs to earn 9,750 xps. He will reach 9th level right before everybody else reaches 10th.
I'm working on this in excel right now, but let's throw some preliminary numbers out. In order to calculate expected values I first made some assumptions:

The party is composed of 4 characters.
Characters begin with 6000 XP. This makes them 4th level.
Characters gain XP by defeating encounters of CR==party level. (XP is calculated using this calculator (http://www.d20srd.org/extras/d20encountercalculator/).)


Firstly, a correction: characters reach 9th level after receiving 36,000 XP. At this point, a character with a 20% multiclassing XP penalty would have accrued 31,904 XP (8th level).

Skipping ahead again, after amassing 105,825 XP, a standard character would achieve 15th level. At this point, a character with a 20% multiclassing XP penalty would have accrued 97,581.6 XP (14th level).

We can already see that the difference in XP is growing.

[Sagetim]

So, to start with, how are you getting multiclass xp penalties that high at that low level to start with? You need a disparity of levels, and you ignore favored class when calculating that, and prestige classes don't count. So, just to be clear, don't you need a few more levels to get the disparity that's going to get you to a 20% or more? As I recall, Elminster is something like 1 rogue, 2 fighter, 3 cleric, 20something wizard (favored class) and some archmage (a prestige class) and his multiclass penalty is only 20% or something. So you might need a bit more than level 4 to get the percentage you're talking about.

That aside, assuming you could get multiclass penalties that high, the impact is pretty painful. I've never been in a dnd game where you get individual xp awards, it's based on average party level. So even if you're low enough level to bring the average down, everyone is still getting the same xp awards at the end of the session. Which means that the simple math presented is pretty much how it would play out. Furthermore, if you were trying to do any kind of magic item crafting or particular spells, that xp penalty would hurt all the more from 3.5's terrible rule about eating your xp to enchant things. So among other things, the xp penalty is going to pidgeon hole you out of any role that involves you spending xp, because it would just make you lag behind the party that much harder. And some levels that's going to matter a lot more than others. Like levels where everyone else is getting higher spell level's and feats when you're only just getting the extra spells of the level behind everyone else, or...nothing. Then again, if the distribution of your class levels if giving you multiclass xp penalties in the first place, you probably aren't being competitive in maximum spell level or what have you compared to the rest of the party anyway. So that brings me to the question: what is your character going to even be good at?

I may be remembering the multiclass penalties wrong, but don't they start at 10% and add 10% for each extra class in the disparity range? So, for example, an elven fighter 3/ranger 1 wold have a 10% penalty because wizard is the favored class for elves and the classes in question have more than one level difference between them. Then if that character grabbed rogue 1 as well, they could wind up with a 20% multiclass penalty because of the disparity between fighter and ranger and also between fighter and rogue. Meanwhile if they had gone fighter 3 ranger 2 instead, they would have eliminated their multiclass penalty, and if they went fighter 3 ranger 3, then rogue 1, they would have a 20% penalty. But if they went fighter 3, ranger 2, then rogue 1 that would only be a 10% penalty for the disparity between fighter and rogue, then fighter 3 ranger 2 rogue 2 would be no multiclass penalty.

So yeah, am I remembering multiclass penalties right?

[thoroughlyS]

Alright, I've compiled all the data into a table, and prepared 3 charts to help explain my point.

XP Progression by Encounter (https://docs.google.com/spreadsheets/d/1B3P_GLCkoe9dwrNYGAGo44izX_AJIvpGPfhOaDbnsXI/pubhtml)

What this all boils down to is that with a 20% multiclassing penalty, you basically spend half of your time a level behind everyone. A 40% penalty pushes you further, and you spend almost the whole game behind by a level, slipping behind by 2 levels for around 2 encounters at a time.

It is important to note that this is a BEST CASE scenario, where your group faces an appropriate challenge at all times. If you face weaker challenges, you spend more time behind. You also spend more time behind if your group has more than 4 players.

[thoroughlyS]

So, to start with, how are you getting multiclass xp penalties that high at that low level to start with? You need a disparity of levels, and you ignore favored class when calculating that, and prestige classes don't count.
4th level is actually the absolute earliest you could experience multiclassing penalties. You just need to be X 3/Y 1 where X and Y aren't your favored class. So a Half-Orc Ranger 3/Scout 1 would have these penalties. The only races that can't receive penalties this early are Humans and Half-Elves, which need at minimum X 3/Y 3/Z 1.

So yeah, am I remembering multiclass penalties right?
Not quite.

Uneven Levels: If any two of your multiclass character’s classes are two or more levels apart, the strain of developing and maintaining different skills at different levels takes its toll. Your multiclass character suffers a –20% penalty to XP for each class that is not within one level of his or her highest-level class. These penalties apply from the moment the character adds a class or raises a class’s level too high.
Races and Multiclass XP: A favored class (see the individual race entries in Chapter 2: Races) does not count against the character for purposes of the –20% penalty to XP. In such cases, calculate the XP penalty as if the character did not have that class.

[heavyfuel]

Alright, I've compiled all the data into a table, and prepared 3 charts to help explain my point.

[snip]

What this all boils down to is that with a 20% multiclassing penalty, you basically spend half of your time a level behind everyone. A 40% penalty pushes you further, and you spend almost the whole game behind by a level, slipping behind by 2 levels for around 2 encounters at a time.

It is important to note that this is a BEST CASE scenario, where your group faces an appropriate challenge at all times. If you face weaker challenges, you spend more time behind. You also spend more time behind, if your group has more than 4 players.

Dude, that's AWESOME! Thank you for taking the time!

It's actually not as bad as I thought it would be. I was thinking the characters would stay WAY behind, like, 6 levels or so by the time the rest of party is lv 20

Anyway, thanks again!

[druid zook]

Jsketchy, that was good work. I did an informal guesstimate once that led me to believe that an XP penalty is equivalent to a level adjustment. Would you care to perform an analysis on this?

Specifically, I was looking at imposing a 33% XP penalty in a three-player gestalt game, and I remember a DM who imposed a +1 LA for gestalts in his game. I'm interested in your findings.

[Frozen_Feet]

I was about to come in and say "in practice with a 20% penaltj you lag a level behind starting with when the penalty kicks in". But I see the math's already been done.

As for LA comparison, 20% penalty is sort-of like LA+1 and 40% LA+2. The actual effect depends on what you are getting out of your hodge-podge of classes?

[Afgncaap5]

Nice to see the actual math presented!

As it is, I've always enforced this rule in straightforward 3.5 games, mostly because I have a sort of "we won't change it unless it comes up" thing. I think the only place where something like it comes up in my games is that I've told players that "half-elves can have two favored classes" (which I'm borrowing from Pathfinder, even if "favored class" means something very different in that game.)

So far, with my ruthless, totalitarian enforcement of this grossly unjust rule, it has yet to affect a single player, mainly because multiclassing hurts their build choices more than it helps them so they don't want to anyway.

[thoroughlyS]

I did an informal guesstimate once that led me to believe that an XP penalty is equivalent to a level adjustment. Would you care to perform an analysis on this?

Specifically, I was looking at imposing a 33% XP penalty in a three-player gestalt game, and I remember a DM who imposed a +1 LA for gestalts in his game. I'm interested in your findings.
For my two cents, look in the second "TREATED AS HIGHER LEVEL" spoiler.

Alright, let's get a few things out of the way. By "+1 Level Adjustment", I assumed you meant that your friend treated their players as if they were 1 level higher for the purposes of determining XP awards. I included that, as well as the expected results of using the LA buy-off variant.

I went back and re-calculated everything, starting from 1st level. These numbers were derived according to some refined assumptions:

These represent the XP earned by a character in a party of 4. The other three hypothetical characters are single classed with a +0 LA race.
Characters begin as early as is allowed by the rules, with a starting XP value equal to the amount expected by a character of that level. For example, the +1 LA calculations start when the hypothetical party is level 2. They also start with 1050 XP instead of 1000 XP, because a character stating at level 1 is expected to earn 1050 XP before becoming level 2.
Characters gain XP by defeating encounters of CR==party level. (XP is calculated using this calculator (http://www.d20srd.org/extras/d20encountercalculator/).)

Below is the raw data for 8 different scenarios:

No multiclassing XP penalty, no LA, treated as a character of their level (Base)
20% multiclassing XP penalty
40% multiclassing XP penalty
+1 LA with buy-off
+2 LA with buy-off
+3 LA with buy-off
Treating the character as 1 level higher for determining XP awarded
Treating the character as 2 levels higher for determining XP awarded

XP Progression by Encounter (https://docs.google.com/spreadsheets/d/1B3P_GLCkoe9dwrNYGAGo44izX_AJIvpGPfhOaDbnsXI/pubhtml#)

As before, I whipped up some handy charts to illustrate the results.

http://i.imgur.com/0EkLG2A.png
This is a little cluttered, so I have broken it down into the 3 different issues we're looking at here.

http://i.imgur.com/gmEf7rs.png
The results for multiclassing XP penalties are nearly identical, which is to be expected. Starting at level 1 had almost no effect on the numbers here.

I corrected an error I made in my previous post, which is that it is impossible to have the 40% penalty until level 5.

http://i.imgur.com/3wiXaJ3.png
It is interesting to note that all three level adjustments end up reaching 20th level by the time a baseline character would reach 210,000 XP (which would bring it into epic levels). Just another reason this should be used at every table.

Reading through the raw data, I found out that the cost for reducing a +1 LA to +0 almost disappears by 14th level. The only time it matters after that is that the +1 LA character actually hits 16th level earlier by one encounter. After that, it acts just like the base progression. The +2 LA progression actually gets an XP bonus after 17th level. That's a free 104 XP.

http://i.imgur.com/sewJZe3.png
This chart actually resembles the multiclassing penalty chart, but just a little worse. Just like the 40% penalty, being treated as 2 levels higher means you do not reach 20th level before the baseline character would reach 210,00 XP (reaching epic levels).
http://i.imgur.com/DXvGs39.png

http://i.imgur.com/Y0sUpMX.png

http://i.imgur.com/G2v5Cze.png
http://i.imgur.com/iRdqeo7.png
For LA buy-off I show both ECL and character level compared to the base. This gives you a better sense of your capabilities in relation to those of your party. I find it interesting how quickly the +1 LA catches up.

http://i.imgur.com/tM9nsod.png
I'm not convinced that this is a reasonable answer to gestalting. I don't believe that it keeps up with the radical shift in power at higher levels. A 19th level gestalt character is still leaps and bounds ahead of an ordinary 20th level character in the same role. I'm assuming this is for balancing gestalt and non-gestalt characters, because in a game where everyone is gestalt, the rules shouldn't really change.

I was about to come in and say "in practice with a 20% penaltj you lag a level behind starting with when the penalty kicks in". But I see the math's already been done.
I feel that this is misleading. Firstly, you don't lag behind until the level after you gain the XP penalty (e.g. a Barbarian 3/Wizard 1 is still 4th level just like the other players, and it isn't until the others hit 5th that you feel the XP difference). Secondly, you are only underleveled about half the time. The rest of the time, you are the same level as your party members.

The 40% penalty is where you really feel it, as you spend almost 50% more time at 5th level, which puts you half a level behind everyone else. From there you slowly slip into being a full level behind for the rest of the game.

As for LA comparison, 20% penalty is sort-of like LA+1 and 40% LA+2.
If by "LA" you mean "treated as a higher level for the purposes of determining XP awarded", that is an accurate comparison.