The Dark Assembly is a recurring feature in the Disgaea series..
At the other side of the castle, Laharl and the members of his party may appear before the Dark Assembly, an area where non-player characters may vote on proposals to aid Laharl's party, including proposals to unlock special maps required for some of the endings or secret characters. Senators have a visible predilection toward or against the party that affects their votes. Said predilection can be affected by bribes with items from the player's inventory, which carries on from one session to the next. Each proposal to the Dark Assembly costs "mana", which is built up by characters as they defeat enemies. The amount of mana gained depends on the enemy's level. If a proposal fails to receive sufficient votes, the player may attempt to pass the bill anyway by choosing to "persuade by force" and defeating the opposing senators in battle. The proposals available to place before the senate depend on the number of promotion examinations completed by a character; these examinations consist of a battle with a handful of monsters on the floor of the Assembly; you can reach an "examination level." The senators also count as normal monsters when you persuade by force, so if you defeat a senator that's a new type of monster then you can use that class in character creation and reincarnation.
A possible prototype for Disgaea 2: Cursed Memories' Legendary Senators, called "Proxies," may appear occasionally when proposing a bill. "Proxies" are special senators that are actually Laharl's vassals in the castle. They are always Humanoid and are easliy distinguishable. In this installment, however, they have no special functions, behaving similar to a normal Senator, though they may be equipped with weapons if fought, making them possible item sources.. Also, if the "Proxy" is defeated in order to force a bill, they will become unavailable in the Castle, a tombstone taking the character's place in the castle, and you will not be able to access their normal functions (ie buying items, going to the item world, etc.). A quick save and reload will cause them to respawn and appear in the castle, and their normal functions will resume.
Note: Once you defeat Baal and Laharl receives the title of Lord of Terror/Tyrant, bills proposed will almost always succeed.
By talking to the Dark Secretary in Holt, Adell can visit the Dark Assembly. Players choose one character from those available in their party to bring up a list of resolutions available to that character. Mana gained by defeating enemies in combat is used as a kind of currency in the Dark Assembly. Each resolution requires a cost of a certain amount of mana. Merely paying the mana required does not automatically pass a resolution; it must be voted on by senators. Unlike Disgaea: HOD, when you are selecting a bill to propose at the Assembly, you will be given a percentage on how likely the bill is to pass. Bills that require more Mana or that generate a larger effect (such as opening a secret dungeon) have lower chances than that of a lower cost bill.
Once a resolution has been chosen, the view changes to a large auditorium with randomly selected senators. Each senator has a disposition toward the character proposing a resolution. This is the Netherworld, so it is perfectly acceptable to bribe senators with items in the item bag. Giving a senator the right items will improve their disposition toward the character (honest senators, usually those in the White Dragon party specifically, will not take any bribes no matter what the situation; giving them a Bribe will actually lower their favor towards the player). After bribing, senators will vote based on their disposition. If the yeas beat the nays, the resolution passes. Even if a bill loses the vote, the player can choose to "persuade by force". A base panel appears and the player can attempt to beat the opposing senators. If all opposing senators are killed, the resolution will be passed. Using "persuade by force" with lower level characters is very dangerous, as senators are more powerful than lower levels can handle, and losing means game over.
New to Disgaea 2 are the Legendary Senators, a special type of Dark Assembly senator with various abilities, all of which will radically alter the Assembly environment. Legendary senators have a very powerful voice (their votes count for far more than any other senator) and they will all create some sort of effect before casting their vote. For example, Legendary Senator Ares will strike an adjacent senator on his row, blowing away all senators on that line and eliminating their votes. Legendary Senator Venus will emit a magical aura that will force all adjacent senators to vote along with her, regardless of their dispositions beforehand. While bribing the Legendary Senators alone may not pass a bill for sure, not bribing them is nearly a surefire way to ensure a bill will fail: attempting to "Persuade by Force" with a Legendary Senator in attendance leads to a fight which the player is very likely to lose, if the legendary senator votes against the player, as all Legendary Senators are at least level 1000.
Additionally, as the game carries on, Adell can also gain access to the proposal of "I Want To Become A Senator". If passed, Adell will become a senator and can sit in and vote on special assembly sessions, such as raising the voice power of different parties. When Adell first becomes a senator, his voice is 30. The player can increase his voice by passing the "I Want More Voice Proposal". Each proposal passed increases Adell's voice by 30 points to a maximum of 120. Note that having Adell become a Senator is the only way to access many of the game's Special Stages, containing recruitable characters. While a senator, you are still able to "Persuade by Force", however during these fights you can only use Adell. It is often a good idea when Adell is a low level to make sure there aren't any Wood Golems, as they can usually regain health faster than you can deal damage.
In Disgaea 3: Absence of Justice, the Dark Asssembly is known as the Classroom Assembly. In this installment, Senators rely on certain items that appease them rather a general Rarity ranking. (I.E: Succubi favor Belts, though sweets also win their favor)
The Dark Assembly is instead referred to as the Dark Senate. (In keeping with this installment's political theme) The Senate functions much like the Classroom Assembly from the previous game, with Senators having specific Items that they prefer to be bribed with.
However, this installment, being the first to offer online support, allows appointed characters to visit other players' Senates as Foreign Ministers. Ministers behave much like the Special Senators from Disgaea 2, being given a pre-determined gimmick that can affect the vote. (I.E: Disabling other Senators' votes by ejecting them from the meeting or putting a Party of Senators to sleep, ETC.). A new addition is the Cam-pain Board Evil Symbol, which allows party members, including Valvatorez, to participate in the Senate. Those party members cannot be bribed, but they will not necessarily vote "Aye" either, and will attack the player just like every other senator should they vote "Nay" and the player decides to pass a bill by force.
Note that should a Foreign Minister's Behavior be set to accept a Bribe, the type of Bribe they will accept randomizes per Senate hearing.
Disgaea D2's system functions much like Disgaea 3's Class Assembly. Upon proposing a bill, a Chairman will oversee the Assembly hearing. The Chairmen function like the Special Senators of Disgaea 4, with gimmicks that affect the vote. (Such as sleep magic or requiring a specific item to bribe them with)
Like the previous installment, the player's party members can also attend the hearing and vote on the bill, and are also bribe-able. High-level monsters can also serve the same function, and can easily sway the vote.
Each Senator party has items they prefer to be bribed with. (IE: Dragons prefer Emblems, Prinnies like Food items such as Flans, and so on) Rare and Legendary items, lacking numerical ranking, are now accepted universally across the Assembly, with Legendary items being the most effective.
The newest mechanic is the ability to bribe the Assembly with a HL donation should the bill not pass. Like the passing of a Bill, this has a chance to fail, though failing the donation will not refund the player.