Posted by EarthDragon on 11th October 2015.
Most of the rules on how magic actually works and functions within The Unification are the same as in any D&D campaign, and are as outlined in the Players' Handbook, with the very large exception of Spell Points.
In the Chosen Of The Unification campaign, nobody mucks about memorising spells, everyone who casts spells is a spontaneous caster. Sure, they have to learn a spell if they are not a divine caster, and it must be recorded somewhere in some form of spell book for an arcane caster, but nobody actually memorises it the night before and hopes they have a need to cast it the next day; there is no need to agonise over a spell list wondering which spells to prepare for the next encounter and hoping you pick the right ones. In The Unification, if you know it or have access to it (for a divine caster), you can cast it when you need it - if you have the spell points for it and you're the right level.
The table for each spell-casting class contains several important columns which govern spell points. The first is the number of spell points available per level. There is also a column for divine casters with access to domain spells which lists how many domain spell points they have at any given level. Domain spell points are identical to regular spell points except that the can only be used to cast domain spells, unlike regular spell points, which can be used to cast any spell known, including domain spells. The number of spell points available to a caster for the day is vitally important, once they run out, that's it, no more spells for the day, not until the caster gets some rest and either some meditation or some study of the old spell books to refresh their minds of the general formulae of the spells the know. The amount of rest required varies from four to eight hours and is defined in each class description (as is whether study, prayer or meditation is required).
Spell casters with a high score in their primary casting ability will get bonus spell points due to their score. These are added to their total number of regular spell points for the day and are used up just like any other spell point. There is nothing otherwise special or different about them, they're literally just a bonus. How the character uses them (whether on regular spells, metamagic feats or domain spells, if applicable) is entirely up to the character.
The other important column in the character class table is the maximum level of spell that a character can cast at their current class level. This determines what spell list the character can choose to cast a spell from, and also determines how much the character can "boost" the spell with metamagic feats. For example, if a metamagic feat causes a spell to occupy a spot one level higher than normal (by quickening it, for example), then the character must be eligible to cast a spell one level higher than the base level of the spell in order to cast the enhanced version of it (i.e. a quickened magic missile, for example, is a 2nd-level spell, so a 1st-level character cannot cast it even though they have enough spell points to do so).
The number of spell points required to cast a spell is simple to determine. First, take the level of the spell in its unaltered form from the appropriate spell list for the character (beware, a spell may be on more than one spell list, and more than one list may apply to a character; the correct list must be chosen for the type of spell points chosen), then add any additional levels required by any metamagic feats applied to the spell to determined the effective spell level of the spell. This effective spell level is the number of spell points required to cast the spell.
Cantrips (0-level spells) are treated slightly differently. Although they are 0-level spells, it does not take 0 spell points to cast a cantrip. The first time a cantrip is cast on a given day, a single spell point is expended, which allows the character to cast up to 5 cantrips that day before requiring another spell point to be expended. If the character rests to recover spell points before casting the full 5 cantrips allowed by the spell point expenditure from the previous day, the remaining castings for that day are lost and a new spell point must be expended to cast new cantrips once the rest period has been completed.
Note that the savant character casts spells from both an arcane spell list and a divine list, and has two distinct sets of spell points, one for each list. Similarly, a multi-class character must maintain a separate pool of spell points for each spell-casting class, even if both spell-casting classes cast the same type of spell, unless the second class is a prestige class that specifically extends on the first spellcasting class (for example, a prestige class that extends on the casting ability of the san-li). Thus, a san-li/wau-ken would have two pools of arcane spell points to keep track of because although they are both arcane spell casters, they access their powers in slightly different ways and have different spells available to them; san-li spell points cannot be used to cast wau-ken spells, and vice-versa, though if the same spell is on both lists, a spell could be cast from either set of points. Generally, this separation of powers is required when multi-classing into two base classes that are spell-casters, but is not typically required when one spell-casting base class is taken and is extended with an appropriate prestige class. The DM will advise if there is any exception to this rule.
For ease of reference, a page has been provided within the Magic section which combines all of the spell point information for all of the base classes and all of the prestige classes. Likewise, the spell lists for all base classes and prestige classes has also been provided as combined pages. These include spells from the Players' Handbook and other sources (which are identified in the tables for reference).
Because all casters are now spontaneous casters, there are a few subtle changes required to the rules involving metamagic feats. These relate to how the change to preparation of spells enhanced with metamagic is handled and how casting time is affected.
The rule in the Players' Handbook about casting time and spontaneous use of a metamagic feat does not apply in this campaign. Metamagic feats are still more difficult than casting a spell without it, but this is reflected in the extra cost of using the feat and the limitations on how many levels of enhancement may be applied to the spell, not the impact on casting time stated in the original rules. All the standard casting times in the spell descriptions apply as normal when casting a spell without a metamagic feat, and are unaltered when casting with a metamagic feat, unless the purpose of the feat is to alter the casting time (such as the quicken spell feat).
Applying a metamagic feat to a spell causes it to "ocupy a spell slot" of a higher level than it normally does, typically causing someone to have to memorise it as a spell of a higher effective level under the standard rules. Thus, a silent charm person is a 1st-level spell in all respects when it comes to the dice, but it is treated as a 2nd-level spell when it comes to spell points, including when it comes to how high a level of spell a character is entitled to cast. This means that a character who wants to cast such a spell must be able to cast spells of a minimum of 2nd level, even though the spell is still only a 1st-level spell in every respect that does not have to do with the number of spell points it costs. Typically, this means a 3rd-level caster or higher for a class that is primarily a spell-caster.
This means that there is a cap on how high a level of spell a metamagic feat can be applied to for any given character and, technically, means that no 9th-level spell can ever have a metamagic feat applied to it that would raise its cost to 10 or higher. Only characters that can cast epic spells can modify a 9th-level spell with a metamagic feat if it would raise the spell's spell point cost to 10 or higher, and even then, it can cost no more than 11 points to cast. This 11 spell point cost limit for epic spell-casters applies to all spells getting metamagic feats applied to them, and applies only to epic spell-casters, everyone else is limited to only as many spell points as the highest level of spell they can cast (i.e. no more than 9 at most for a 20th-level character). An 11-spell poinst 1st-level spell would have had significant modification, but would be within the realms of possibility for an epic spell-caster to toss off casually in the course of an encounter if they thought it would come in handy.
If the standard rules describe a metamagic feat as causing a spell to occupy a slot "one level higher", then it costs one spell point more than usual. Similarly, if it would occupy a slot "two levels higher", it costs two more spell points, etc. This spell point system is a straight level-for-point system, and is considerably simpler than the system that was introduced as an alternative in the 3.5 source Unearthed Arcana, and these rules take precedence over those in that source.