The game add contains most of the info. This is a game where you can build your BBEG and actually play them in a campaign with other BBEGs to obliterate those goodly, orderly fools that dare oppose you. So it is a pretty high-power game with lots of epicness.
Do note however that while powergaming is not a bad thing, don't make characters that aren't playable. Because I reserve the right to use this;
On the 28th of Tarsakh 1385 DR, a lone, heavily wounded and crippled Solar appears in Dweomerheart out of thin air and asks for an audience with the goddess of magic. Less than day later Toril-time, the high priests of Cyric the Mad all across the world are struck dead in various horrible accidents, from spells going awry and magic items exploding, to roof tiles breaking off for no reason and falling on their heads while they cross the streets below, to swarms of bees making their hives in their bedrooms and stinging them to death while they sleep, to other far more ridiculous forms of demise. At the same day, lesser priests of the Mad God lose their powers and are struck with more than their usual insanity. Within a month, the Church of Cyric lies in ruins.
That is but the beginning. Natural disasters, magical mishaps, unbelievably bad luck and other woes befall the major bastions of organized evil in the world at the same time every divine or goodly order in the Cosmos launches a concerted campaign against them; the entire church of Shar has to leave Toril for Tartarus to avoid a similar fate to Cyric's forces. The vast majority of devil cults, worshippers and everyone that ever dealt with the Nine Hells is either slain or imprisoned, their ordered tyrranies upon the face of Toril crushed to the ground. Spellcasters serving those forces of Order and Good seem stronger than ever, using their powers to obliterate any danger to the stability of Toril, hunting down entire populations of evil monsters - such as the chromatic dragons - to near extinction.
For ten years the unbelievably bloody conflict rages across the world, no kingdom remaining untouched in the wake of Armageddon. As angels and good dragons and wizards become far more numerous and involved in the affairs of the world, monsters and evil gods alike are pushed ever back, with fewer and fewer territories in their control. Soon enough, no hiding place will be left for them on the face of Toril, all those who oppose the divine order forever gone...
Or will they?
Powerful monster survival/epic vs the oppressive forces of Good!!!
A solar time-travels from the post-Spellplague Forgotten Realms and warns Mystra and Azuth of their upcoming murders. Forewarned and prepared, and facing the destruction of the Weave, Mystra slays Cyric then sacrifices herself so that the Weave will be embodied within every spellcaster everywhere and no longer be succeptible to tampering or destruction. Seeing those events and learning of Shar's plot and Asmodeus plans to murder a god for his divine essence, the good and neutral gods have had enough. They band together and wage war upon the evil gods while their followers systematically eradicate any monsters and other dangers to the stability of Toril. The world is ravaged by the war but is also slowly being purged of monsters and hidden evils, possibly signaling the beggining of a new age of prosperity.
1) The PCs are powerful monsters the lesser races once held in awe or even worshipped as gods, rulers of their respective domains. They now face extinction as those lesser races band together, their champions and the heralds of the false gods of good and order hunting them down.
2) The game starts with the PCs trying to lay low in a remote area of the world when they're attacked. They decide to band together in the face of Armageddon, either succeed in stopping the forces arrayed against them or die in defiance.
3) This will be a high power game that is also going to be hard. After all, you'll be playing as monsters that no longer want to be bags of loot and XP with legs.
Is required. Making a good villain character can sell me the idea and up your chances of picking you. Also, a fleshed-out character is more fun to roleplay. Given that you'll be in a party of villains and monsters, flavor is more important than in the generic heroes-beating-monsters setting.
(OK, flavor is always important - but you get the idea)
1) You make a CR 20 monster character. That's CR following the monster rules in the SRD, not I repeat not the ECL rules used for normal PCs. You can use a straight CR 20 Balor and customize it, or take a lower CR monster and add racial HD, class levels or even a template or two.
2) SRD monsters of base CR 7 or higher are usable provided they are intelligent (end intelligence of 9 minimum), make sense flavor-wise and has some understandable personality. I.e. no half-dragon half-troll anything and no giant dragon insect things, gibbering mouthers and the like
3) For ability scores modify your basic creature's stats with the BBEG array of 18/16/14/12/10/8 and one ability increase per 4 HD; you are heroic specimens of your race, after all. But because I want this game to be about your characters rather than your bling, you may NOT benefit from enhancement, deflection or resistance bonus from items. The extra abilities even out with the lack of bonus - you end up being as strong as monsters with +X items without everyone and their mother actually buying them, which you would end up doing.
4) You got 500.000 gp you can buy items with but only items from the SRD. The exception is one personal weapon or armor (including amulet of natural attacks).
5) Most base classes count as unassociated. Spellcasting classes you already have innate levels in (such as with a dragon and sorcerer levels or a planetal and cleric levels) count as associated. Prestige classes count as associated.
6) Those of you with spell-like abilities can exchange them for others of equal or lower level if you want to personalize your monster. Healing SLAs over lvl 4 are limited to 6 uses/day. Metamagic SLAs are possible. Especially unbalancing spells (celerity, gate, wish, miracle and the like) are not available.
7) You can personalize your monster's appearance to make them unique but keep the mechanics the same. I.e. a demon character can look more or less inhuman, to your preference. A tarrasque character can look like a muscular, green, raging giant.
1) Loopholes that intentionally exploit oversights in the system or questionable rules interpretations. I.e. pun-pun, omnificer.
2) Antimagic no longer exists. An AMF works like a globe of invulnerability blocking magic abilities of its effective level and lower.
3) Disjunction no longer destroys items in an area. It merely dispels them for 2d4 rounds. To destroy an item, it can be targeted upon a single item as if it were a targeted dispel.
4) If you use Shapechange or a similar ability to mimick a major special attack or supernatural power of the assumed form, the spell's power is used up.
5) I reserve the right to use this; http://media.photobucket.com/image/b.../BanHammer.png
Having dwelt in the depths of the world for over twenty thousand years, Urlaghast is one of the most knowledgeable and cunning of the solitary aboleths; growing in power on its own terms, feeding even on others of its kind to absorb their memories and skills. As a survivor of this primordial race, whose vast cities were unable to halt the advancing tide of the young faiths, it falls to Urlaghast to ensure a future for itself and its offspring. If it can exterminate the upstart races and end their threat permanently in the process, so much the better.
So... under your character creation rules, I could play a level 20 kobold sorcerer if I wanted?
Kobold base CR is lower than 7. Thus no, you can't play as one. The reason for this rule is to encourage people to play monsters rather than fairly normal characters that happen to have a different base race.
Rules for health, what books we can use?
Health is average. For books, you can use any 3.5 Edition WotC book (but not magazines or their compilations) plus 3rd Edition books that may not have been updated such as Savage Species. If something is too overpowered will be decided on a case-by-case basis because the same thing in one build may be OK but may also lead to brokenness in another.