Preferred classes and xp penalty

[medea]

I am getting conflicting answers so I thought I'd ask here.

Preferred classes and xp penalty. Does a preferred class have to be the highest class to avoid the penalty?

Example and questions:
Let's use elf with wizard as preferred class.

Can I have an elf with one level of wizard and 20 of fighter and avoid xp penalty? Or are the classes too far apart, despite the fact wizard is the preferred class?

Also, is it true that a preferred class does NOT have to be within a certain amount of levels to the other classes to avoid xp penalty?

Example and questions:
Let's use elf/wizard again.

Can I have an elf with 12 wizard and 3 fighter and avoid xp penalty? Or will I be penalized because the classes are too far apart?

I originally thought that preferred classes didn't count at all. You didn't have to worry about whether it was the highest class level and/or how close it was to your other levels.

I would very much appreciate an official explanation from the Team as I want to be certain I understand this rule fully. Thanks!

[Alphonse]

Preferred class and a regular class - no penalty ever.

Prefered class, a regular class and a PrC - no penalty ever.

Regular class and PrC - no penalty ever.

Two regular classes within 1 level of each other (with or without a PrC third class) - no penalty

Two regular classes more than 1 level apart (with or without a PrC third class) - 20% penalty

Two regular classes within 1 level of each other and a prefered class - no penalty

Two regular classes more than 1 level apart and a prefered class - 20% penalty

Three regular classes more than 1 level apart - 40% penalty (I think)

[medea]

Thank you very much for posting it so clearly and concisely!

Follow-up question. How is all this affected if the character is an asimar or a tiefling since they are automatically given one level of Outsider?

[Adament]

Do the custom races preferred classes work or do they take from the base class for xp penalty?

Example is my wood elf ranger. If he takes any other class there should be no penalty but if the code uses preferred class for just elves then it is wizard and if he takes anything beside wizard then he would get 20% penalty?

Waas

Age of post indicates I was trying to do my research lol