This campaign setting is a continuation of the things discussed in Thoughts on D20 Modern and Pathfinder. I'm moving over to a new thread because enough changes were made to the materiel posted in the OP to make the OP non-indicative of the setting. This is a setting using a modified Pathfinder system.
This setting takes place on an Earth where magic exists out in the open, and people live alongside elves and dwarves. It is set in the modern day so far as technology and culture are concerned, though the styling is a mix of 50s/60s retrofuturism and gothic fantasy. It is intended for games involving Van Helsing/Underworld style monster hunters or monster PCs, James Bond/Sam Fisher/Jason Borne style special agents, Call of Duty style military characters, or Law and Order/Harry Dresden style detectives. The name Guardian comes from the fact that the setting mostly focuses on heroes working for various government agencies, guarding that nation's people by eliminating violent monsters and rogue mages, thwarting terrorist plots, or fighting off military threats.
To make this OP not a gigantic wall, I will split the remainder into spoilered sections.
History
With the existance of magic, history took a very different path. Some things, like the British capture of Quebec, the unifications of Germany and Italy, and the rise of a great British Empire, still happened, if in slightly different ways, but other things went very differently. The rebellion of the 13 Colonies was put down, the French Revolution never occurred, Napoleon lived his life as a successful general rather than as an emperor, Washington and Oregon are a provence of Canada, Britain and Spain eventually fought over North American colonial possessions, which ended with Cuba and California in British hands, and the 13 Colonies gained their independance from Britain in the same manner as Canada and Australia, and as five seperate nations, not one.
This setting focuses on Great Britain and her former colonies, France, and Germany.
Magic
Basically, instead of an Arcane/Divine divide, I have a Mystical/Scientific divide. Witches do not have patrons, and rely on a spellbook rather than a familiar (they can still gain a familiar if desired).
Assorted other details
You really only need one iterative attack. It's not like the other two do much. Looking towards Trailblazer in implementing this change.
Firearms should use an average of Str and Dex for attack and damage. This is to discourage combat focused characters from boosting Dex to rediculous levels while ignoring other stats. It is explained by recoil.
Full attacking should be a standard action to facilitate a more mobile style of combat.
Spellcasters no longer have a stat to govern their spellcasting. Instead, the relevant stat is determined by spell school. Each class has increased spells per day to compensate for the loss of bonus spells. This is to prevent spellcasters from boosting their spellcasting stat to rediculous levels while ignoring other stats.
I don't know what to do about automatic weapons and exposives yet, but no fixed Reflex saves like D20 Modern.
Probably going to go with a Wound/Vitality system.
Money can be handled by tracking characters' bank accounts. I'd only pay attention to big purchases, ignoring little things that don't matter like fast food or gas, so it shouldn't be too hard to do.
As for D20 Modern's background system, I'm looking towards a hybridization with the Pathfinder trait system. I'm looking towards making backgrounds a trait category and having players select one trait from each category at character creation. I want to tie class skills to this system rather than classes, so that how you grew up effects what skills you've developed. Each trait would have five associated skills, and you'd pick three from each trait you have.
There are a LOT of vampire myths IRL, and they have very different attributes. For example, a Filipino vampire looks absolutely nothing like a Stokerian vampire, and a Draugr is something else entirely. I want to take a similar position in my setting, with there being a lot of dramatically different types of vampire, united only by a thirst for blood or psionic energy.
Some areas have magical power. This is what causes phenomena like haunts and enchanted forests. Halloween and Christmas have similar magic power in locations where they are celebrated (both holidays are common among Christians and most western Pagans, though some Pagans call the days Samhain and Yule or All Souls and Midwinter). Easter or a related Spring holiday and Midsummer would have this power if they were given the level of excitement and anticipation Halloween and Christmas are given, but they are not.
The Headless Horseman exists, and facilitating this is the only reason I retained a colonial rebellion against Britain within this setting.
Elves
Elves tend to have an artistic bent, though it is as likely to be towards literature, song, performing, or the like as to be towards painting, carving, sculpting, or the like. Then lean towards creativity in general, and are known for being very passionate in whatever they do. They lean towards a natural cleverness that makes many of them skilled in strategy, whether military, economic, or political. A very large number of elves have some degree of mental disorder, most often bipolar disorder, depression, sociopathy, or paranoid schizophrenia. They form addictions very easily, with alcoholism being highly common and caffeine addiction almost expected of them, and a statistically large number are disposed towards narcissistic, hyperactive, attention seeking, or self destructive behavior. Essentially, elves have a powerfully creative but fragile mind.
I'll hopefully have more posted within a week, but I start my freshman year of college in the morning, so we'll see. I'd love feedback or questions, and I'd also appreciate advice for what to do about Dwarves and Orcs. I want them to be a playable Fae race like Elves are, but I can't think of what to do with them.
Dot.
Might I recommend using a Sanity score in addition to the usual ones? This would help out with the Elves mental problem without reducing Wisdom, Intelligence, or Charisma.
Making there be a difference between physical agility and manual dexterity may also be a good idea and would balance the Mental/Physical traits if Sanity is used.
I look forward to more about this setting, though I wonder how this would work out on a world that is not Earth...
I'll have something more on this on the weekend, unless a professor drops a gigantic homework assignment (I don't expect this from German or Math, but I'm adding History tonight and have no idea if the prof there will want something done). I'm currently working on a basic history of the setting and a map.
Might I recommend using a Sanity score in addition to the usual ones? This would help out with the Elves mental problem without reducing Wisdom, Intelligence, or Charisma.
I was planning it as a detail of the culture, not as something with a rule effect on the player, because the average PC either doesn't have mental issues or is high functioning. The PCs work for people who don't like crazies.
In games I play on Facebook there are research points. It can be an individual count on the second character sheet. For simplicity I think it should accrue at a point an hour for library research. It can add +1 a point to any knowledge skill use. Possibly any other int. or wisdom based skill. When someone designs technology they can buy designs with research. Experiments can gain the inventor 25 research + modifiers.