I have thought that for some time there is not much that a true caster can really take for casting in the way of feats, and while I GM most of the time in our games it has caused many castes to not want to play a true caster route because in their words, in terms of feats there is not as many options for us to chose from. (If I am wrong and there are good magical feats to be taken please let me know as well as commenting about my house rules) I am somewhat new to house ruling but think this should be ok.
To this end we looked at Metamagic Feats and as they seem the most logical place to start for a true caster here is what I came up with and wonder how it might play out. Understand this, myself and the players I play with believe that magic should be far more powerful in scope then simply using a bow or another weapon, its magic and should therefore be fantastic. (When I play I play Barbarians/Fighters/Clerics/Rogues (typically archers for rogues) and the players I play with are really into playing the class they want to play not just, who gets the most kills, but really who can have the most fun with the character that they are playing at that time.
Here is how I have the rules written as of now for my players, please let me know what you think.
For all metamagic feats there will be no more increasing of spell level, only a level requirement for that feat. Also I will work it like the feat Stunning Fist. For clarity for everyone, I have included the important piece of the part of Stunning fist we will be using for a basis. A monk receives Stunning Fist as a bonus feat at 1st level, even if he does not meet the prerequisites. A monk may attempt a stunning attack a number of times per day equal to his monk level, plus one more time per day for every four levels he has in classes other than monk.
So what that means for a caster that chooses a metamagic feat, you may choose to amplify for spells with your chosen feat a number of times equal to your level in that casting class. You simply then apply your feat to any spell and take it off your list for that day. Example, Verul a 10th level Wizard has chosen the metamagic feats Empower Spell and Maximize Spell. He can then empower or maximize any spell that allows him to do so. So he chooses Fireball. He is 10th level, and therefore may use Empower spell and Maximize Spell 10 times per day. If he chooses he may combine both, however he would go down to 9 uses of each of that feat for the day. Also if you are playing a half caster such as ranger or paladin, you have uses equal to 1 for every four levels in that class. So a 9th level Paladin can do a maximized Cure Light Wounds 2 times per day. Again I am making this change to allow for more creativity and I believe this will help in that goal. For the basis of each metamagic feat I am using the system of how many spell slots you had to give up x3 for most of the feats in order to make calculations on what level you will be having access to your feat. Example: Enlarge spell normally would use 1 spell slot higher, and 1 times 3 equals 3, therefore you will have access at level 3.
Empower Spell — Increase spell variables by 50% Level 6
Enlarge Spell — Double spell range Level 3
Extend Spell — Double spell duration Level 3
Heighten Spell — Add + 5 to ones spells CAB Level 3
Maximize Spell — Maximize spell variables Level 9
Quicken Spell — Cast spell as a swift action Level 12
Silent Spell — Cast spell without verbal components Level 3
Still Spell — Cast spell without somatic components Level 3
Widen Spell — Double spell area Level 9
Advanced Players Guide
Bouncing Spell — Redirect a spell that had no effect on initial target Level 3
Dazing Spell — Daze creature with spell damage Level 9
Disruptive Spell — Target of spell must make concentration check to cast a spell in the next round Level 3
Ectoplasmic Spell — Spell fully affects incorporeal and ethereal creatures
Elemental Spell — Inflict energy damage instead of regular spell damage Level 3
Focused Spell — Increase save DC of spell for one target in a group Level 3
Intensified Spell — Increase maximum damage dice by 5 levels Special*
Lingering Spell — Instantaneous area effect spell lasts for 1 round Level 3
Merciful Spell — Spell inflicts nonlethal damage instead of lethal Level 1
Persistent Spell — Creatures who saved against a spell must save again Level 6
Reach Spell — Increase spell range to higher range category Special**
Selective Spell -- Exclude targets from an area effect spell Level 3
Sickening Spell — Sicken creature with spell damage Level 6
Thundering Spell — Deafen creature with spell damage Level 6
* You may select this feat at level 1 but must use it on spells you have had for at least 2 levels.
** You may select this feat at level 1, for every step up you must have 2 levels, example if you wish to make a spell from touch to long, being 4 steps, you must be at least level 7. (1,3,5,7) you must take all previous steps in order to gain the next.
Burning Spell — Spell with the acid or fire descriptor deals extra
damage the next round Level 6
Concussion Spell — Spell with the sonic descriptor gains a
debilitating concussive effect Level 6
Echoing Spell — Cast a spell a second time Level 9
Flaring Spell — Spell with the fire, light, or electricity descriptor
dazzles creatures it affects Level 3
Piercing Spell — Affected spell treats creatures with SR as having
an SR of 5 lower Level 3
Rime Spell — Spell with the cold descriptor also entangles
creatures if the spell damages them Level 3
Thanatopic Spell-- Affected spell’s death effects, energy drain, and
negative levels affect undead Level 6
Threnodic Spell -- Change a mind-affecting spell so it can affect
undead, but not living creatures Level 6
Toppling Spell — Spell with the sonic descriptor knocks targets prone Level 3
... what ...
This is by far the most overpowered house rule I've ever heard. Anyone who isn't a full caster will be absolutely destroyed.
Being able to Quicken or Maximize a spell once per day (without changing the spell level) would already be a good feat. Allowing it to be used caster level/day means almost every single spell will be Maximized, Empowered, Quickened, etc., especially at high levels.
If you want to make this rule, I'd highly recommend making it once/day instead of caster level/day.
For reference, you're basically taking the feat Spell Perfection, probably the best feat in the game for spellcasters, and one that requires you to be 15th level and have taken 3 other feats, and giving a better version of it to everyone at level 1 (Spell Perfection does double bonuses, but it only applies to one spell.)
Good feats for casters:
Greater Spell Penetration
Greater Spell Focus
Greater Spell Specialization
And depending on what type of caster you are:
1. Use the level as a pool and subtract the level increase from the pool. 10th level Wizard can use a 1 level boost 10 times per day and a 4 level boost twice per day.
2. Use the level as a pool and subtract the spell unmodified spell level from the pool. 10th level Wizard can Maximize a first level spell 10 times per day or a 5th level spell twice per day.
I've always been bothered by Metamagic feats and this really illuminated the issue for me.
I think, if you want to give player's more options as casters, give them more things to do with their spells.
What I've been doing is, whenever a player wants to try something that a spell might be able to do but doesn't explicitly, they make a Spellcraft check. For instance, if a player wants to use Soften Earth and Stone in a line instead of in a radius.
Talk to your players and figure out what sort of things they want to do, and figure out a fair way to do it that everyone can agree on. There are guidelines for creating spells and other sorts of things.