i.e. Fighter/Magic-User starts at levels 1/1, splitting xp between the classes and each class needing level 2 xp before they hit 2/2. HPs would be 1/2 of the two HDs rolled at the same time (i.e. 1d10 + 1d4/2).
the split xp would be fine as all classes use the same xp chart in 3E, but it would basically double the xp needed to level up - allowing single classes characters to hit level 2 3 and then 4 as the dual classed hits 2/2.
any thoughts?
Lilaxe, based upon your initial assertion, I believe the existing dual classing capabilities of the game would work exactly as you describe. A dwarf fighter/cleric, with the only notable exception at 1st level, when they would be all fighter or all cleric, but with an approrpirate feat allocation, you could still play and feel like a "figther/cleric" from the word go. At 20th level you would be a 10 Fighter/10 Cleric (exactly as you describe), and would look and feel different from straight fighter builds and straight cleric builds. What's fun about the 3e version is that the character can truly "evolve" through their career and may choose to over-specialize in one side or the other, ending up a 13 Cleric / 7 Fighter or vice-versa, or go a completely different direction, like Hammer of Moradin. The bigger challenge with 3e dual/multi classing has been that when you "fall behind" your peers in any category, it's difficult to pick up the slack. For example, a 12th level party with a 6th level cleric caster will have real difficulty "keeping up" with the healing required, the powerful magics that need dispelled, and removing/slowing the powerful conditional effects that villians will have at 12th level - ability drains, level drains, poisons, and disease.
If your assertion was that by 20th level, the dwarven fighter/cleric would actually be 16/16, but with "half hit point" dice and "toned down" but "full power" abilities from both classes, that is interesting, but very challenging to execute and balance effectively. The beauty of the 3e system is the inherent balance built into it,and the general availability for everyone to participate/benefit. If the "only" limit is XP, but the fight/cleric can churn and burn through xp faster because of their superior abilities (a distinctly 1e flavor), then this disrupts that inherent balance built into 3e, and really contradicts the recommended xp system (even flow to all players based upon accomplishments) established in the 3e DMG. This xp basis is also a "conceit" to the game, due to the dramatically increased complexity and challenge built into the scale of the game. The difference between 3rd level and 9th level PC's in 1e (original) was pretty minor, and these PC's could interact meaningfully in a set of challenges together. The difference between 3rd and 9th in 3e is monumental, and the 3rd level PC is likely to have the floor wiped with EL9, 10, and 11 encounters, while the 9th level PC could single-handedly cake walk EL 3, 4, 5 encounters.