There are a few house rules on multi-classing.
Characters must choose certain classes at the start, or never be allowed to choose that class. This applies to:
I am using the optional rule on 1st level multi-class characters from the 3.0 Dungeon Masters Guide page 40.
The character is considered an apprentice in both classes until they reach enough XP to be second level. At which point they become 1st level in both classes.
Weapons and armor proficiencies and skills are gained for both classes.
Player chooses one class to be the primary class and the full hit points for that class. Upon reaching second level, they get the hit points from the second class. The character does the same thing for skill points, using primary class to determine number of skill points and what is considered a class skill. Starting gear or money is done as per the primary class. The character gets all the benifits of both classes except as noted. in the table below. For special abilities they only get the special abilities listed in the table for both classes.
Apprentice level spell casters know as many spells as a first level caster, but can only cast as indicated per day. Apprentice level casters do not get bonus spells. Both of these restrictions go away at 2nd level. As an apprentice wizard they do get specialty spells as normal. An apprentic cleric gets only a single first level spell which is choosen from one of his two domains.
Turn undead, lay on hands and detect evil are level based. Treat the apprentice as 0th level for purposes of these special abilities.
| Spells | ||||||||
| Class | BAB | Fort | Ref | Will | Special |
0th lvl | 1st lvl | |
| Fighter | 0 | 1 | 0 | 0 | 1 bonus feat | |||
| Barbarian | 0 | 1 | 0 | 0 | Rage, fast movement | |||
| Paladin | 0 | 1 | 0 | 0 | Detect evil, lay on hands | |||
| Ranger | 0 | 1 | 0 | 0 | One favored enemy | |||
| Wizard | 0 | 0 | 0 | 1 | ||||
| Sorcerer | 0 | 0 | 0 | 1 | ||||
| Cleric | 0 | 1 | 0 | 1 | turn undead | |||
| Druid | 0 | 1 | 0 | 1 | ||||
| Rogue | 0 | 0 | 1 | 0 | ||||
| Bard | 0 | 0 | 1 | 0 | ||||
| Monk | 0 | 1 | 0 | 1 | unarmed combat, Wis bonus to AC | |||
Multi-classing is tougher than the standard D&D rules. Classes can not just be added, they have to learned. This learning can occur over time between adventures or in a single block of time.
Increasing an existing class of a multi-class character follows the same level up rules as for single class characters.
Adding a class that is not related to an existing class requires the same amount of time to learn as a starting character. See the table below for time. See class descriptions for special requirements. These numbers are derived from the Random Starting Ages table 6-4 on page 109 of the DMG. House rule interpretation is that the random factor for character starting ages depends upon when a person starts their training, their intelligence and their masters willingness & ability to teach. The wide difference in races has more to do with maturation within the species than with learning ability is my house ruling.
| Class | Years to Learn | Special Requiremetns |
| Fighter | 1/2 to 2 | |
| Barbarian | N/A | |
| Paladin | 2 | Yes |
| Ranger | 2 | Yes |
| Wizard | 4 | |
| Sorcerer | N/A | |
| Cleric | 4 | Yes |
| Druid | 4 | |
| Rogue | 1 | |
| Bard | 2 | |
| Monk | 2 | |
| Interdimensional Traveller | N/A |
Requires two years to learn if a wizard, sorceror or similar poor combat class. Takes one year if
Requires two years with the Paladin's organization. This can be cut to 6 months if the character is already a fighter or ranger.
Clerics of certain gods will have to have other classes than cleric to advanced. Those classes do not take the time specificied in the table above. Instead, they are learned during initial training, and added with the same level up time as a regular cleric advancement.