General Rules for Template Classes
The following rules apply to the "class version" of any template.
• A character may take a level in a template class as long as the DM approves and the character has earned enough XP to gain a level.
• The DM may wish to require an appropriate ceremony, quest, ritual, or experience before allowing a character to gain levels in an inherited template class. This same option also applies if a character wants to gain levels in an acquired template class without the appropriate trigger (such as an attack by a wereboar to acquire the afflicted wereboar template).
• Template classes follow the normal rules for template acquisition according to creature type. For example, the wereboar template can be added only to a humanoid or giant. Thus, a half-dragon character (whose inherited template has already changed his type to dragon) could not take levels in the wereboar class.
• Unlike the regular template rules as given in the Monster Manual (see Adding More Than One Template, Monster Manual page 293), this variant rules system allows a character to gain levels in a desired inherited template class after gaining levels in an acquired template, if desired. (In effect, these rules turn all inherited templates into acquired templates that have special circumstances for acquisition later in a character's life.)
• The DM should disallow certain redundant combinations of monsters and templates. For example, it makes no sense for a hound archon to gain the celestial or half-celestial template, since it is already a kind of celestial.
• A character cannot take levels in a template class if she already has that template or has taken all the levels in that template class. For example, a natural wereboar (a character who already has "wereboar" as an inherited template) cannot take levels in the wereboar template class.
• Characters are not required to complete all the levels of a given template class in uninterrupted succession. For example, a character who takes a level of wereboar could then take a level of fighter and a level of rogue (or any other combination of other class levels) before taking another level of wereboar. A character must still take the first level of wereboar before taking the second, just as with a normal class.
• Each level in a template class increases the character's level adjustment by +1, just as would a level of any other character class.
• Template class levels can be lost due to any effect or circumstance that would normally cause a character to lose a level.
• Levels in a template class do not count when determining whether a character takes an XP penalty for multiclassing.
• In some cases, a certain monster ability presented in the Monster Manual for a given template is split over two or more class levels in a template class (often by limiting how often an ability can be used at the start). Alternatively, variant abilities may be introduced to build toward an ability that is too powerful for a lower-level character. In these situations, the template class features section explains how the ability works at each level. By the time a character has acquired all possible levels in a template class, the completed set of abilities relating to that particular function works exactly like the normal ability described in the Monster Manual.
Example: In the vampire template class presented below, the template class has abilities called alternate form (lesser) and alternate form (greater). The description of the alternate form ability given in the class description explains that the vampire initially has access to only two of the vampire's normal alternate forms (bat and wolf) but will eventually be able to assume the other two forms (dire bat and dire wolf), as described in the Monster Manual.
Example: In the vampire template class, the character slowly becomes more resistant to critical hits and sneak attacks via the fortification armor special ability. This ability thread culminates in immunity to those attack types once the creature finally gains the undead type. At that point, the fortification ability becomes redundant and can be ignored, and the vampire built with all levels of the template class works exactly like one built with the Monster Manual template.
• Unlike standard character classes (and the "monster classes" from Savage Species), most template classes do not increase Hit Dice, base attack bonus, base saving throw bonuses, or skill points with level. They also do not affect when a character acquires feats, since feat acquisition is based on HD, not ECL. However, some of these aspects of the character can be affected indirectly by alterations in Hit Die type, ability score changes, special attacks or qualities, bonus feats, and so on.