Multi-class vs mixed-class characters

As I mentioned recently, after starting purely with basic Labyrinth Lord, we've had several "Advanced" style multi-classed demi-human player characters created in my campaign in the last few months. I've been thinking about the introduction of these characters and how it's changed the game.

The main influence they've had, I feel, is an unfortunate one. Their ability to do two things well has tended to overwhelm the single-classed characters, with very little downside. A thief / magic-user is equally as capable as a normal thief and a normal magic-user. As they have to split their XP between two classes, multi-classed characters gain XP in each of their classes at half the normal rate. However, while a 50% reduction sounds like a big deal on paper, due to the exponential nature of the XP progression charts this effectively means the characters are only one level behind their single-classed companions. This in my experience makes little difference (a single spell per day for MUs, or a few percentile points for thieves, for example), and is more than made up for by the fact that they are all round so much more capable. This, in combination with demi-humans' substantial racial benefits, makes multi-classed demi-humans far and away more powerful than their single-classed human brethren, at the low to mid levels of play, at least.

So I've been thinking about why players might want to create multi-classed characters. Several reasons come to mind:

1. To try something different. In a game with only three or four classes, allowing them to be combined in pairs greatly increases the number of possibilities.
2. To play a character of mixed class.
3. To counteract the level limits applied to demi-humans, by effectively slowing down the race towards the end point.

Today I want to address the second of these points -- the desire for a character that's "a bit of a thief, a bit of a wizard" or something like that. I think that players with such ideas in mind (the dabbling bard or magical assassin archetypes, for example) don't expect their character to be as good a wizard as a single-classed magic-user, or as good a thief as a single-classed thief. They simply want to have a mixture of abilities -- an option which is not presented by the strictly separated classes of standard D&D. Ignoring the odd dual-classing rules of AD&D, multi-classing is traditionally the primary way to create a character with mixed abilities.

I've been contemplating an alternative. Instead of giving a mixed-class character the complete abilities of two different classes, how about giving them half of the abilities of each of those classes? I think in essence this is actually more what players are imagining when creating mixed-class characters.

Of course what exactly constitutes half of a magic-user's, fighter's or thief's abilities is open to interpretation, and would depend very much on the rules set being used.

Here's an example of the kind of thing I'm thinking of, in terms of the standard Labyrinth Lord classes.

Mixed-Class Characters
Characters can choose two classes, and gain roughly half the abilities of each.

Mix-classed characters have the following characteristics in general, modified by the chosen classes:

• XP progression: as magic-user
• Hit Dice: d6
• To hit rolls: as thief
• Saving throws: best of two classes
• Weapons & armour: as thief

Half a Magic-User
Cannot create magic items.
Can use magic-user specific magic items from 5th level.
Labyrinth Lord's call as to whether mixed-class magic-users can cast spells while wearing armour.
Use the following spell progression:

Level    1    2    3    4    5
1    1*    -    -    -    -
2    1    -    -    -    -
3    2    -    -    -    -   
4    2    -    -    -    -
5    2    1    -    -    -
6    2    2    -    -    -
7    2    2    -    -    -
8    2    2    1    -    -
9    2    2    2    -    -
10    2    2    2    -    -
11    3    2    2    -    -
12    3    2    2    -    -
13    3    2    2    1    -
14    3    2    2    1    -
15    3    3    2    1    -
16    3    3    2    1    -
17    3    3    2    2    -
18    3    3    2    2    -
19    3    3    3    2    -
20    3    3    3    2    1

* A 1st level half magic-user must make a successful INT check on 1d20 each day to learn a spell.

Half a Thief
Choose three of the following (advancement as normal thief):

1. Pick locks & find / remove traps
2. Pick pockets
3. Backstab
4. Climb walls
5. Move silently & hide in shadows
6. Hear noise

Half a Fighter
Can use all weapons.
Can use fighter specific magic items from 5th level.
Choose two of the following:

1. d8 Hit Dice
2. Fighter attack progression
3. Use any armour
4. Use a shield