The Disgaea D20 utilizes various additional rules to the Pathfinder RPG, For the normal Pathfinder rules it would be best to refer to the Pathfinder SRD Basics and Ability scores page.  The Variant rules however are described here, Among these variant rules are those such as...
Hero Points (Introduced in the APG)  Traits (Introduced in the APG)  Vehicles (Introduced in Ultimate Combat)  Firearms (Introduced in Ultimate Combat)  (The usual Disgaea campaign setting is used with the "Guns Everywhere" setting). If utilizing futuristic firearms as the Earth in the Disgaea world tends to possess superior technology, you can utilize the rules for technological equipment as well. http://www.d20pfsrd.com/equipment---final/technological-equipment
Additionally there are many other rules developed specifically for this system.
EVILTIES: Every character starts with one Evilty granted to them at first level, This evilty is determined by their character class. A Character can purchase more Evilties with mana, but can only ever have 2 equipped at a time Unless leveling up as a monster class in which you can utilize 3. When Utilizing the magichange monster combat maneuver, you also gain access to the starting evilty of the creature you have Magichanged with. A list of those Evilties is located on the "Evilties" page.
MANA: Mana is gained from enemies you defeat in battle. Mana is earned by each creature at the end of an encounter. Each member gains a number of mana equal to the Challenge Rating of the creature. More information about mana can be found on the "Mana" page.
TECHNIQUES PER DAY: Every class has Techniques per day. These techniques can be learned utilizing the Technique Learning process at the beginnings of the "Martial Techniques" page. These techniques are performed much like one casts a spell, however the saving throw of the technique is described in the technique's description, usually based on the weapon utilized. More on Techniques Per day is located in the "Martial Techniques" page.
NEW COMBAT MANEUVERS Edit
LIFT AND THROW: As a Full round action, you can lift and throw an ally or opponent a number of squares equal to your strength Modifier. This of course can only be performed on an adjacent creature. Lifting is a standard action and throwing is a move action, so of course you can choose to not carry out the full effects of the lift and throw in a single turn. Characters being held can attempt an escape artist or an opposed grapple check against their opponent’s CMD or not be able to do anything for the round. You can hold them for a number of rounds equal to your constitution modifier -1 for every other person you are holding. If trying to hold an enemy it is the same as starting a grapple. It is also possible to catch tossed characters if playing as another humanoid character. Monsters cannot throw, however they will instantly launch a creature a number of spaces equal to it’s strength modifier if thrown at. Creatures held can attack with small or natural weapons while held and have the same penalties as if being grappled.
Any monster type creature can magichange with a humanoid into a weapon which is determined by your type. Magichanging is a free action. A Magichange lasts as many rounds as your Constitution Mod +3 (Charisma modifier if you lack constitution), and when changed back the character is exhausted, even if you are usually immune to that condition. This exhaustion cannot be cured by magic, or through means other than resting for 1 hour.
When Magichanged, the wielder gains the use of the first evilty of the magichanged monster. The user also gains a +1 magichange bonus to an ability score for every 2 in the monster weapon’s relevant ability modifier which is listed in the monster’s description. (For instance, Juju the prinny transforms into a gun for his sexy partner Binky to wield. He has a Dexterity of 18, giving him a +4, and thus granting Binky a +2 to her dexterity).
Any special techniques the wielder can use with this weapon can still be used as normal. Finally, the wielder gains the use of the monster’s special weapon techniques that can only be used while the monster is in weapon form.
The weapon is treated as a masterwork weapon of it’s type and the weapon gains a +1 enhancement bonus. For every three levels beyond 1st, the weapon gains another +1 enhancement bonus, to a maximum of +7 at 20th level. These bonuses can be added to the weapon to a maximum of +5. or they can be used to add any weapon property by consuming an amount of bonus equal to the property's cost. Duplicate abilities do not stack. At least a +1 enhancement bonus must be added before any other properties can be added.
The chance to land a critical hit also increases by one point per 10 levels and it stacks with abilities like keen or improved critical but is always added in AFTER the feat has been calculated. Also, the distance of ranged weapons increases by 5 feet/level. Damage dealt is equal to the monster’s natural attack damage or their monster weapon damage, whichever is higher.
Finally, ranged weapons do not use ammunition for magichanged weapons, however if you possess ammunition that you would like to utilize with the monster, you can do so, so long as it is compatable.
Any monster type creature can Fuse with another monster into a larger monster. Fusing is a free action and you must be next to the creature you wish to fuse with. A fusion lasts as many rounds as your Constitution Mod +3 (Charisma modifier if you lack constitution), and when changed back the character is exhausted, even if usually immune to being exhausted, and they lose 1/2 of their remaining techniques per day. This exhaustion cannot be cured by magic, or through means other than resting for 1 hour.
When Fused, the creature with the highest level gains control as well as determines the type of the base form. If different, the creature gains the use of the first evilty of the fused monster. The user gains a bonus to his own ability scores equal to the bonuses or penalties of the other creature. (For instance, Juju the prinny fuses with Captain Grande` the prinny. He has scores in this order 12, 18, 14, 10, 12, 9, giving the fused monster a +1, +4, +2, +0, +1, -1) to his scores. In addition, the creature increases by 1 size category and takes a -2 penalty to dexterity and a +2 size increase to Strength and Constitution as well as a +2 to natural armor. The monster’s natural attack (Or monster weapon) damage increases by one size category.
The Fused Monster gains a trample attack that works on any creature at least one size lower than them.
As a full-round action, a creature with the trample ability can attempt to overrun any creature that is at least one size category Smaller than itself. This works just like the overrun combat maneuver, but the trampling creature does not need to make a check, it merely has to move over opponents in its path. Targets of a trample take an amount of damage equal to the trampling creature’s Natural attack damage, or Monster Weapon damage, whichever is equipped + 1-1/2 times its Str modifier. Targets of a trample can make an attack of opportunity, but at a –4 penalty. If targets forgo an attack of opportunity, they can attempt to avoid the trampling creature and receive a Reflex save to take half damage. The save DC against a creature’s trample attack is 10 + 1/2 the creature’s HD + the creature’s Str modifier (the exact DC is given in the creature’s descriptive text). A trampling creature can only deal trampling damage to each target once per round, no matter how many times its movement takes it over a target creature.
In addition, the Monster’s special attacks increase in range by 5 feet. Monsters whom are fused are super dense and therefore cannot be moved through techniques that move you unwillingly, as in special attacks or through the Drag Combat maneuver. Fused monsters cannot be lifted.
This works identical to magichanging however it can only be performed on a monster who has already been magichanged. The abilities of magichange stack with the first magichanging and allows for the weapon to be used as either the first or second monster’s magichange weapon type. It also grants the wielder every one of the Monster techniques (Or unique techniques if possessed) the 2nd magichange partner possesses. This shortens magichange time by ½ of whatever the current time is and when the magichange ends the monsters are considered to be helpless and unconscious. This cannot be utilized if the monsters possess an evility that causes their magichange ability to last for an infinite period of time.
This works identical to magichanging however it can only be performed on a Humanoid who is already holding a magichange monster. The abilities of magichange do not stack with the first magichanging, however you are treated as if you were wielding these weapons as if two weapon fighting. In addition, as a full round action you can use two techniques that require a standard action to perform. When the magichange ends the monsters are considered to be helpless and unconscious.
This works just as Magichange but with the statistics of a Fusion monster. The weapon type becomes that of the monster whom is taking control of the body in the fusion. The weapon increases in size by one size category and if the weapon is too large for a creature to wield normally, they must utilize the monkey grip feat to wield the weapon without taking the usual penalties listed for wielding weapons of a size category too large. The weapon's damage dealt is a combination of the base damage from both weapons, or a combination of the base damage dice from their monster weapons, and it uses the better critical hit multiplier as well as the better critical hit range of the weapons. A fusion magichange lasts for only 1/2 of the normal number of rounds a magichange normally does. Finally the range of the weapon increases by 5 feet if a melee weapon or 10 feet if it is a ranged weapon. (For example, Dingo the Dragon and Ralphie the Zombie fuse to make a single creature. Dingo is of a higher level so he takes control of the body. When magichanged, they transform into a spear, as it is Dingo's magichange type. the damage they deal is 1d10 from the spear, and 1d8 from Ralphie's Pistol damage. their critical hit range is a 20, and their multiplier is X4 which was increased from the spear's typical multiplier of X3 because of the Pistol's critical hit multiplier.)
Mounted Combat can be performed by a humanoid and a Monster class. The Humanoid rides atop the Monster and enters into battle using the monster as it's mighty steed. The Human cannot be more than 2 sizes larger than the monster it wishes to mount and both must be willing. While atop the monster, both creatures act on whomever has the lower initiative from then on. The monster gains any benefits that the rider would give to a mount it is riding, and both gain benefits from any mounted abilities at this time, Finally, the monster grants the humanoid creature the same ability bonuses it would as if it had fused with another monster. On a Mounted monster's turn, it cannot attack, however it can charge and move normally. The rider is not considered as having moved and can take it's actions normally, including a full attack, even if the monster had them move. While mounted, the Rider can use any of the Monster's Magichange Techniques, and can also use any spells of their own, but not techniques. To Dismount, the rider can take a move action, or the Monster can take a move action to buck them off gracefully to allow them to retain their move action for the round.
LIFT ATTACK: To use this maneuver you must be at the bottom of a lift chain and have an attack action ready. Upon making your attack against their CMD, you deal damage as usual and allow the next person in the line a free attack against the opponent. This person gains a +1 to attack and damage and this bonus increases by +1 for every person in the chain. Once the attack ends, the target is placed back in front of the chain. This action is initiated by whomever is on the bottom of the chain and takes away the other actions of everyone involved.
New Status Ailments Edit
DEFEATED: When Defeated, you need to pay money to heal the character. You can be dead for a number of days equal to your level. If the character cannot afford to be brought back to health. At the time of death, they can use mana to transmigrate into something new (at Lv. 1), and if they cannot afford that either, they are revived as a prinny, unless otherwise stated by the DM.
FORGET: When a character has FORGOTTEN, they can not use any Special techniques they have utilized until the effect wears off. Some versions make spells unavailable as well.
DEPRAVED: Depraved creatures gain 50% less EXP if they are depraved at the end of an encounter. In addition they take a -2 penalty to each ability score. Different levels of Deprivation, like different levels of fear effects, stack and therefore with each Depraved penalty you receive another -2 penalty to each score. (Minimum 1)
New Skills Edit
Martial Knowledge: Described on the Skills page.
WEAPON TYPES: The weapon types have been expanded as well as combined. The weapon types no longer go by “Martial, Simple.. Ect…” They now follow the same pattern as the Fighter’s weapon training with a few modifications.
Axes: battleaxe, dwarven waraxe, greataxe, handaxe, heavy pick, light pick, orc double axe, and throwing axe.
Blades (Heavy): bastard sword, elven curve blade, falchion, greatsword, longsword, scimitar, scythe, and two-bladed sword.
Blades (Light): dagger, kama, kukri, rapier, sickle, starknife, Beam Saber, and short sword.
Bows: composite longbow, composite shortbow, longbow, and shortbow.
Close/monk: gauntlet, heavy shield, light shield, punching dagger, sap, spiked armor, spiked gauntlet, spiked shield, unarmed strike, kama, nunchaku, quarterstaff, sai,
shuriken, and siangham.
Crossbows/Firearms (light): hand Gun, hand crossbow, light crossbow, Remote, and light repeating crossbow.
Crossbows/Firearms (Heavy): heavy crossbow, heavy repeating crossbow, chain gun, bazooka, rifle, flame thrower, and Makai Cannon.
Double: dire flail, dwarven urgrosh, gnome hooked hammer, orc double axe, quarterstaff, and two-bladed sword.
Flails: dire flail, flail, heavy flail, morningstar, nunchaku, spiked chain, and whip.
Hammers: club, greatclub, heavy mace, light hammer, light mace, and warhammer.
Natural: unarmed strike and all natural weapons, such as bite, claw, gore, tail, and wing.
Pole Arms/spears: glaive, guisarme, halberd, ranseur, javelin, lance, longspear, shortspear, spear, drill, shovel, and trident.
Thrown: blowgun, bolas, club, dagger, dart, halfling sling staff, javelin, light hammer, net, shortspear, shuriken, sling, spear, starknife, throwing axe, pie, UFO, and trident.
- Monster: Physical, Magic
Novelty: Drum, Book, Syringe, Fan, Magnet, Frying pan, Box, Fishing Pole, Bomb, Wrench, Improvised, and Balloon.
- Can only be taken if the Fighter has reincarnated as a monster or is of the monster type.
Just like in normal Pathfinder, there are many different languages. However due to the setting for Disgaea there are many different languages that apply to this world instead.
Though it works the same, as a reference to the Disgaea games, Common is set to Japanese or English, depending on which version you plan on using when you run. This has no actual in game difference (Unless you want to maybe have someone stuck speaking English while everyone else speaks Japanese and no one can understand him) It is just a fun throwback to the actual games.
In addition to shoes each monster has it's own language it can speak in.
Disgaea D20 "Epic Levels": Reincarnation Edit
Geo Symbols Edit
Just like in the game, the Disgaea D20 system utilizes special objects known as Geo Symbols. Whenever starting a battle or planning out landscape, always remember that you can roll for, or select some geo Symbols and geo panels to place in the area so as to give combat a little extra edge. [wiki:disgaead20:"Geo Panel Abilities"]