Multiclass penalty
From NWNWiki
If a multiclass character's classes are not nearly the same level, then he suffers a multiclass penalty of -20% XP for each class that is not within 1 level of his most experienced class. These penalties apply from the moment the character adds a class or raises a class's level too high. For instance, a 4th-level Wizard/3rd-level Rogue gets no penalty, but if that character raises his Wizard level to 5th, then he'd receive the -20% penalty from that point on until his levels were nearly even again. The penalty is -40% if all three levels are uneven, for instance, a 5th-level Wizard/3rd-level Rogue/1st-level Fighter.
[edit] Races and multiclass XP
A racially favored class does not count against the character for purposes of the -20% XP penalty. For instance, an 11th-level Gnome character (a 9th-level Rogue/2nd-level Wizard) suffers no XP penalty, because he has only one nonfavored class (Wizard is favored for Gnomes). Suppose he then achieves 12th level and adds a level of Fighter to his classes, becoming a 9th level Rogue/2nd-level Wizard/1st-level Fighter. He suffers a -20% XP penalty on future XP he earns, because his Fighter level is so much lower than his Rogue level.
A Dwarf 7th-level Fighter/2nd-level Cleric suffers no penalty, nor does he when he adds 1st-level Rogue to his classes since his Cleric and Rogue classes are only 1 level apart, and Fighter is a favored class for Dwarves.
A Human or Half-Elf's highest-level class is always considered his or her favored class for purposes of the multiclass penalty.
Human is not always the best choice to avoid an XP penalty: For example, a Human 2nd-level Fighter/8th-level Wizard/8th-level Rogue would suffer a -20% XP-penalty, a Dwarf with the same class combination would not. Humans and Half-Elves can never suffer a -40% penalty.
Because spells such as Shapechange and Polymorph Self and a Shifter's abilities change the core race of a character, Human or Half-Elf multiclassing freedom and Favoured Class bonuses are lost when a character uses these abilities to become another race of creature. In that case, penalties are applied as if the character were naturally of the race of the shape taken.
[edit] Prestige classes and multiclass XP
Prestige classes are exempt from the multiclass XP rule and do not count against the character. For example a 20th-level character (10th-level Rogue/3rd-level Shadowdancer/7th-level Assassin) will not suffer any XP penalties no matter what race the character has chosen.
[edit] Multiclass XP Penalty Table
| Character level | XP | 20% Penalty | 40% Penalty |
| 1 | |||
| 2 | 1 000 | ||
| 3 | 3 000 | ||
| 4 | 6 000 | ||
| 5 | 10 000 | 12 500 | |
| 6 | 15 000 | 18 750 | |
| 7 | 21 000 | 26 250 | |
| 8 | 28 000 | 35 000 | |
| 9 | 36 000 | 45 000 | |
| 10 | 45 000 | 56 250 | 75 000 |
| 11 | 55 000 | 68 750 | 91 667 |
| 12 | 66 000 | 82 500 | 110 000 |
| 13 | 78 000 | 97 500 | 130 000 |
| 14 | 91 000 | 113 750 | 151 667 |
| 15 | 105 000 | 131 250 | 175 000 |
| 16 | 120 000 | 150 000 | 200 000 |
| 17 | 136 000 | 170 000 | 226 667 |
| 18 | 153 000 | 191 250 | 255 000 |
| 19 | 171 000 | 213 750 | 285 000 |
| 20 | 190 000 | 237 500 | 316 667 |
| 21 | 210 000 | 262 500 | 350 000 |
| 22 | 231 000 | 288 750 | 385 000 |
| 23 | 253 000 | 316 250 | 421 667 |
| 24 | 276 000 | 345 000 | 460 000 |
| 25 | 300 000 | 375 000 | 500 000 |
| 26 | 325 000 | 406 250 | 541 667 |
| 27 | 351 000 | 438 750 | 585 000 |
| 28 | 378 000 | 472 500 | 630 000 |
| 29 | 406 000 | 507 500 | 676 667 |
| 30 | 435 000 | 543 750 | 725 000 |
| 31 | 465 000 | 581 250 | 775 000 |
| 32 | 496 000 | 620 000 | 826 667 |
| 33 | 528 000 | 660 000 | 880 000 |
| 34 | 561 000 | 701 250 | 935 000 |
| 35 | 595 000 | 743 750 | 991 667 |
| 36 | 630 000 | 787 500 | 1 050 000 |
| 37 | 666 000 | 832 500 | 1 110 000 |
| 38 | 703 000 | 878 750 | 1 171 667 |
| 39 | 741 000 | 926 250 | 1 235 000 |
| 40 | 780 000 | 975 000 | 1 350 000 |
