Gestalt: As per the
3.5 rules. Dual progression classes are allowed, but you cannot advance an individual class's spellcasting (or any other similar class feature) once on each side. (That is, you cannot do something like Wizard 4 // Druid 3 / Mystic Theurge 1 and claim you have 5 Wizard caster levels.)
3pp/Gestalt interactions: Certain 3pp classes require some adjudication as to how they function in gestalt. Note that these rules are different to the ones on the Spheres wiki.
Gestalt Psionics: If you take two classes that grant PP at the same level, then the PP pools of those two classes are permanently separate, and you can only manifest one class's power by spending PP from that class's pool. Any effects that grant PP that are not from either class are applied to one pool, chosen when you get the ability.
Gestalt Spherecasters: If you take two spherecasting classes at the same level, then you must progress two casting traditions at that level (one for each class, obviously). This otherwise follows the normal rules for multiple casting traditions - there is nothing to prevent your two traditions being identical in terms of drawbacks, boons and ability score. Any ability that grants you extra spheres, spell points, talents and so on applies only to one of the two traditions.
Gestalt Practitioners: In a similar manner to gestalt spherecasters, taking two practitioner classes at the same level means that you have two disjoint practitioner progressions - including a second martial tradition, if both classes grant a martial tradition at first level - and any individual action you take can only be augmented by talents from one progression. Whenever you take a practitioner class, you must choose which of the two progressions the talent(s) you gain at that level apply to - and which of the two progressions your (fractional) BAB applies to for the purpose of determining the effects of martial talents. (Actual attack rolls, no matter what talents they use, still use your full BAB.) For any level where you don't take any practitioner classes, the best BAB from the two classes you do take applies to both progressions. In the case of the prodigy, or any other class who gets benefits from simply possessing a given sphere or talent, they use your full selection of spheres to determine any relevant effects, regardless of where the sphere/talent comes from. Any ability that grants you extra spheres or talents applies to only one of the two progressions. If you have two martial traditions, you may never gain weapon or armour proficiencies (other than simple weapons and bucklers) from a class.
Fractional Base Bonuses: As per the
usual rules, taking the better of each bonus from your two sides at each level as per normal for gestalt. Spherecaster caster levels are also progressed fractionally.
Feat Tax Rules: As per
this article -
not the revamped PDF - with the following exceptions:
- Improved Feint is no longer part of Deft Maneuvers.
- Improved Unarmed Strike and Improved Grapple are merged into one feat and renamed Improved Unarmed Combatant. Monks, and other characters with special unarmed strikes, do not gain Improved Unarmed Combatant; they retain the benefits of Improved Unarmed Strike (even though that feat no longer exists) and their normal unarmed strike abilities.
- Any feat that previously required Improved Trip/Disarm/Dirty Trick/Reposition/Steal now requires Deft Maneuvers, and any Int requirement for such a feat is replaced with a Dex requirement of the same value. Any ability that would let you qualify for combat feats with another ability score instead of Int, or treat your Int as a certain value, allows you to treat such feats as though they were still Int-based.
- Any feat that previously required Improved Bull Rush/Sunder/Drag/Overrun now requires Powerful Maneuvers.
If you get a removed feat (or one you already possess due to a merged group of feats) as a bonus feat, take Weapon Focus instead. If you already have one Weapon Focus, you can take any other combat feat you qualify for.
Other Feat Rules: If you have a natural attack, you qualify for feats and other abilities as if you had Improved Unarmed Strike (even though that feat no longer exists). If you have a special ability like grab or trip that allows you to make a combat maneuver after an attack without provoking, you qualify for feats and other abilities as if you had the appropriate Improved Grapple/Trip/etc feat (even though they no longer exist.)
Background Skills: As per the
usual rules.
Getting Weird Ability Scores to AC: If you have an extra ability score applied to your AC, you only receive the full benefit of this effect if you wear no armour. If you wear armour that the class that granted you the extra AC also grants proficiency with, you may add the relevant ability bonus to AC up to a maximum of your level in that class. If you wear armour that the class that granted you the extra AC does not grant proficiency with, you get no benefit from that ability, even if you are proficient with the armour through other means. This overrides whatever rules exist in the various classes that grant the ability, but does not override any other limits in the ability (for instance, if you are a duelist, you still need to be wielding a weapon and no shield to get the benefits of canny defence.) This rule does not apply if you are actually changing what ability score you add to your AC in place of Dexterity.
Leadership: Leadership and its ilk are prohibited.
Multiple bloodlines, mysteries, etc: All rules of the form "The [insert class feature here]s must be the same type, even if that means that one of them must change." are removed.
Variant Multiclassing: As per the
usual rules, though you still only lose your feats at levels 3, 7 and so on.