Gaile
I've also gone with your standard, Tolkienesque campaign setting.
BACKGROUND
The world is called Gaile (derived from Gaea) and the campaign is set around 6500 years after a cataclysmic meteor strike (a bolt from the heavens) destroyed a large portion of the supercontinent of Gaile, destroying much of central Gaile and creating the western lands of Avandunil and eastern Estegalle.
Little is known of the times before the cataclysm, but scholars and theologians agree that a mighty, united kingdom of men, elves and dwarves held dominion over Gaile. Its people possessed great insights into the workings of the world, unraveling the mysteries of the heavens and earth through the sciences, particularly arcanology, and creating numerous wonders through their arts.
Some hold that the cataclysm came as a result of an arcane experiment gone awry, perhaps through the dark influence of infernal servants of the dark gods, while many believe that "The Hammer of the Gods" came from the heavens as punishment for man's abandonment of the gods of The High Gathering and quest to deify themselves through the use of magic.
What is well known is that, following the devastation, the survivors on both continents clawed their way back from the brink of destruction. Faced with pestilence, famine and years of icy cold, the remaining people of both continents waged a ceaseless war against each other for survival. For countless years, chaos reigns over the shattered lands of Gaile and her people are reduced to savagery, as all semblence of civilization crumbles into ruin.
Nearly 4000 years after the cataclysm the whole of Avandunil was united under the rule of the Avadain (Men of the West), who brought peace, prosperity and the worship of The High Gathering to all corners of Avandunil. Alliances forged between the races of men, elves and dwarves facilitated in the building of cities, roads and brought about cultural and scientific advancements.
In Estegalle, several tribes of humans rose to prominence in their fight for supremacy. The Tribe of Maurid, led by Shardan the Wise, isolated themselves from the constant wars of the north in the southwestern lands beyond a vast desert known to them as The Sheltering Sea. In the southeast the Narahim established their hidden kingdom among the semitropical wilderness that sheltered them from their warring neighbors. In the north, Yssgelundians of the frozen climes engaged in endless bloodshed for territory with the powerful Maelnach tribes of central Estegalle.
The elves and dwarves of Estegalle isolated themselves from these wars and were forced to battle the races of goblins and giants in order to carve out realms in the forests and mountains of the continent. Over the years, the migration and mingling of tribes brought about the Tribes of Vors upon the Plains of Algur, the northeastern Vinnisklad of the frozen wastes and the Kashgari hillmen.
500 years ago the Avadain, having rebuilt their glorious kingdom and brought their people back to the worship of the true gods, sought to bring their benificent reign to the wartorn shores of Estegalle. With a vast armada the Avadain host landed upon the western shores of Estegalle 587 years ago intent upon building a united, Avadain-ruled, kingdom through strength of arms and the blessings of the true gods.
The game takes place in the Common Year 575 (using the Avadain calendar, which began with the construction of their first citadel at Caer Lyon), with the Avadain having fallen short of their goal. Their kingdom upon Estegalle, Caerleon, was wrested from the lands of the Maelnach, who have either been assimilated into Caerleonic society or driven in Caerleon's eastern wilderness but never managed to expand beyond central Estegalle.
To Caerleon's north lies the kingdom of Suttegarde, formerly part of Caerleon until it was ceded to northern conquerers 253 years ago. Suttegarde, now an ally to Caerleon, still faces the depredations of Yssgelundian raiders and its people, worshippers of The High Gathering, no longer consider themselves northmen. In both kingdoms, institutions of learning fall under church control and the few colleges of magic that exist are dedicated to Aethrude, god of magic, and teach theology to prospective wizards.
To its east lie the Plains of Algur and the Three Tribes of Vors, the Carmascians, Sarathians and Voruskai. Over the years their border settlements have grown into small towns and centers of trade but, on the whole, the people of the plains are nomadic by nature, with mounted hordes defending their lands and raiding into the lands of Kashgar, Caerleon and Suttegarde.
Mauridia, under the rule of its deathless emperor (currently reborn in the form of Empress Correna Osriel), has grown in both might and wealth over the years and stands in opposition to Caerleon and its church. Mauridia's people revile the false gods for the wrath that they visited upon Gaile and have come to worship Shardan the Wise as their god. Great centers of learning and trade exist throughout Mauridia's spired cities and its great fleet of ships ensure prosperous, safe trade with the mercantilistic city-states of Kashgar.
Kashgar is the most technologically advanced of Estagalle's lands, the seat of scientific discovery and arcane research... unfettered by the superstitious trappings of religion. Just as Kashgar stands as a center of learning, it is also the predominant trading nation of Estegalle, able to maintain trade relations with Suttegrade, Caeleon, Narahim and Mauridia; and able to protect its interests with a vast warfleet.
RACES
Humans
No ability adjustments
They are played as per the PHB but each culture grants a small, additional bonus to 1 or 2 skills or saves.
Examples:
Avadain - +1 racial bonus to FORT saves versus diseases. +1 racial bonus to WILL saves versus fear effects.
Kashgari - +2 competence bonus to appraise checks. +20% to starting wealth
Elves
High Elves: +2 INT, -2 CON
Sylvan Elves: +2 DEX, -2 CON
High elves and sylvan elves both use the high elf abilities from the core rules, though sylvan elves have ranger as a favored class and both races replace rapier proficiency with short sword proficiency. Dark elves are pale-skinned elves that look much like high elves and have been corrupted by their dealings with Narveg (god of lies).
Dwarves
+2 CON, -2 DEX
Dwarves are played as per the PHB, except that racial weapons do exist and, as such, weapon familiarity doesn't exist either. There is no division between mountain and hill dwarves. Duergar exist as a fallen line of dwarves who betrayed their kinsmen, out of greed, long ago.
Gnomes
+2 DEX, -2 STR
Gnomes are played as per the PHB, except that racial weapons do exist and, as such, weapon familiarity doesn't exist either. All gnomes are much like forest gnomes, but use the standard, rock gnome abilities.
Half-Elves
No ability adjustments
Played as per the PHB, except I replace the skill bonuses to gather information and diplomacy with a bonus feat at 1st level.
Halflings
I don't use them. Gnomes, as I use them in my game, fill the halfling niche.
Half-Orcs
No ability score adjustments
This race deviates the most from its PHB couterpart. Orcs, in Gaile, are synonymous with goblinoids and 1/2 orcs are actually 1/2 hobgoblins. They gain darkvision 60', a +4 racial bonus to move silently, Goblin Blood and favored class: any.
CLASSES
Barbarian Unchanged
Bard Unchanged
Cleric Added Complete Divine domains
Druid Unchanged
Fighter Added Supreme Weapon Focus & Supreme Weapon Specialization as feats.
Monk Unchanged
Paladin Use 3.0 Special Mount ability
Ranger Unchanged
Rogue May choose Hide in Plain Sight as a Special Ability at 13th level or higher.
Sorcerer Use Magic Device replaces Bluff as a class skill. Sorcerers gain Eschew Material Component as a bonus feat at 5th level.
Swashbuckler the only non-PHB core class I allow. The class is modified as follows:
D8 Hit Die, Good FORT and REF saves, and 6+INT skill points/level.
They lose the Grace class ability and gain Shield Proficiency, though they lose swashbuckler abilities that are subject to armor or encumbrance restrictions if they use any shield heavier than a buckler.
Wizard Unchanged
Variant classes from Unearthed Arcana:
Bardic Sage
Battle Sorcerer
Cloistered Cleric
Divine Bard
Savage Bard
Wilderness Rogue
OPTIONAL & REVISED RULES
From 3.0
Weapon Size Rules
Cover and Concealment Rules
Paladin's Mount Rules
From Unearthed Arcana
Spontaneous Metamagic
CALENDAR
The calendar of Gaile has 13, 18 day months. Each month begins with a new moon. The year begins in midsummer and each month has several names, depending on cultural differences. Caerleon and Suttegarde, for example, name each month after a god of the High Gathering.
RELIGIONS
The High Gathering
The is the religion of Caerleon and Suttegarde, as well as that of most humanoids and demihumans.
The Enlightened
The people of Mauridia worship their first emperor and savior, Shardan the Wise as a transcendant being... a true god. To them, the gods of The High Gathering are malevolent beings of great power who nearly destroyed Gaile in their blind fury.
The Order of Geshidra
The people of Narahim worship an aspect of The High Gathering's earth goddess, Gaile, known to them a Geshidra. They believe that her son, the god Danevar (whom they call Riakyo) descended from the heavens following the cataclysm in order to aid them in their time of need. It is thought that he fathered the first High Lord of the Narahim, with a Narahim woman.
Pagan Faiths
Following the cataclysm, many men took to the worship of their ancestors and of nature spirits in place of a pantheon of gods. The Maelnach, Tribes of Vors, Yssgelundians and Vinnisklad are a pagans.
God of the High Gathering
Greater Gods
Name (Alignment) Favored Weapon: Domains
Aluin (LN) Heavy Mace: Law, Inquisition, Protection (God of Rulership)
Jenia (NG) Light Mace: Community, Healing, Protection (Goddess of Motherhood and the Hearth)
Intermediate Gods
Aethrude (LN) Quarterstaff: Force, Knowledge, Magic (God of Magic)
Cerullien (NG) Morningstar: Oracle, Protection, Travel (God of the Stars, Hope, and Sailors)
Gaile (N) Heavy Flail: Earth, Strength, Travel (Earth Goddess)
Lucien (NG) Longsword: Glory, Good, Purification (God of Truth and Purity)
Oredus (NE) Short Sword: Knowledge, Mind, Trickery (God of Darkness and Secrets)
Thandor (LN) Scythe: Law, Pact, Protection (God of Eternal Rest)
Tendellius (LN) Longsword: Celerity, Knowledge, Law (God of Time and Longevity)
Vitian (CG) Longbow: Competition, Healing, Strength (God of Physical Prowess and Health)
Lesser Deities
Dumador (LN) Warhammer: Earth, Law, Pact (God of Forged Oaths and Metalwork)
Faendre (N) Longbow: Air, Travel, Weather (Goddess of the Sky)
Gerian (NG) Light Flail: Creation, Plant, Sun (God of the Harvest)
Haeleth (CG) Javelin: Community, Knowledge, Sun (Sun God, God of Artistic Inspiration)
Illandra (N) Sickle: Dream, Knowledge, Oracle (Goddess of the Moon and Dreams)
Moloth (CE) Scimitar: Chaos, Earth, Fire (God of Fire)
Naeril (N) Trident: Luck, Travel, Water (God of the Seas)
Theros (CN) Spear: Air, Cold, Weather (Storm God)
Demigods
Avellior (CN) Quarterstaff: Chaos, Knowledge, Madness (God of Madness and Visions)
Baloth (CE) Heavy Flail: Destruction, Pestilence, War (God of Slaughter)
Danevar (NG) Longbow: Animal, Celerity, Travel (God of the Wilds and of The Hunt)
Illichor (NE) Longsword: Competition, Evil, Trickery (God of Avarice)
Kharec (NE) Scimitar: Destruction, Purification, Strength (God of Vengeance)
Maredon (LN) Battle Axe: Destruction, Law, War (God of Conquest through Battle)
Miraduin (CG) Shortbow: Community, Domination, Healing (Goddess of Love and Beauty)
Mircueran (N) Quarterstaff: Luck, Protection, Travel (God of Hospitality and Wealth)
Narveg (CE) Shortsword: Domination, Evil, Trickery (God of Lies)
Teunral (LG) Longsword: Law, Good, Protection (God of Justice)
Ulgren (LE) Whip: Death, Destruction, Law (God of Punishment and Death)
Xandemoc (CN) Shortsword: Liberation, Luck, Trickery (God of Luck)