So to expound on my post above, perhaps a brief Disgaea crash course is in order:
So I've never played a Disgaea, but 4 is lookin' pretty nifty. What do I need to know?
1) All Disgaea games take place in one of the apparently many Netherworlds. 4 is specifically referred to as Hades.
2) Prinnies (those cute Penguin looking creatures) are the souls of humans who sinned and have to work off their sins doing the shittiest jobs. Also, they explode when thrown (more on that later).
3) Some Battle Basics to keep in mind, as the tutorial kinda rushes past these in 4.
a) You can bring up to 10 allies into battle with you. Once 10 of your allies are killed, it's Game Over. Doesn't matter how many allies you have/have created. Once the enemy has killed 10 of you, it's back to your last save.
b) At the most basic level, EXP/Mana for gaining levels/powering up abilities is only awarded when a character kills an enemy (exception being Clerics who gain some EXP for healing, but not much). Just because your characters are doing stuff, doesn't mean they're getting EXP for it, like in say Final Fantasy Tactics. If you want a balanced party, it's a good idea to try and let a lower level character lay the final blow to an enemy if they've been reduced to a paltry amount of HP. Note that this isn't the ONLY way to get EXP/Mana, but is the most predominant method.
c) Usually in the Disgaea games, a huge part of the difficulty comes not from the enemies themselves, but from various Geo Panels (colored squares on the map) that have various detrimental effects, or just effects that make the enemy damn near impossible to do damage against until you destroy the Geo Block causing the effect (or throwing it off of said Panel).
d) Speaking of throwing, this plays a HUGE role in making Disgaea's battles unique from pretty much any other SRPG on the market. Many of the battles will require you to throw your allies, perhaps your enemies, or Geo Blocks to win (unless you're extremely over-leveled on a 2nd play-through). So long as it's within a reasonable height, and it's not nailed to the floor, you can pick it up and throw it. You can also pick up characters who are being picked up and create giant towers! Or, if you want to remove an ally from danger, you can pick them up and thrown them back into the Base Panel (the starting panel) if you're close enough. But ONLY HUMAN characters can pick up and throw; Monster-type allies cannot. And again, Prinnies explode when thrown; that includes enemy Prinnies too (kind of a running gag in the series)!
e) Be careful! Friendly-fire is in play!
4) If you want to buy better items as you proceed in the game, you have to improve your Store Rank. You do this by first buying enough stuff to improve your rank, then going to Senate and select the topic "More Expensive Stuff". This is usually easy to get approved, and you can buy better equipment for your party.
5) Lots of the features you want/need for better progress in the game have to be approved by the Senate. It costs Mana to present a topic, and before you select it will indicate via percentage the likelihood of being approved. If you want/need something that might be difficult to get approved, remember the following:
a) You can bribe Senators with various items to get them to lean yes.
b) The higher the level of the Senator, the more weight their vote carries. So when bribing, ALWAYS work high to low.
c) However, some Senators are so dead-set against your proposal, unless you have tons of items they happen to really want, they may not be worth trying to win over.
d) If it is not approved, but you're high enough in levels, you can force passage by fighting and killing all the naysaying senators anyway. Assuming they're not way more powerful than you of course.
e) NEW TO 4, Senators from other players via PSN can jump into your Senate at random to vote. These always start out with the status "Either Way", so keep that in mind.
f) Don't waste Mana trying to get stuff approved over and over. It's a hassle, but save BEFORE going to Senate, attempt to pass, reload if cannot pass.
6) The Item World is the way to get the most powerful items, however it's mostly unnecessary in the early going, and leveling up low-level items is kind of a waste of time anyway as you'll end up just buying better weapons later on anyway. >> It's only really necessary for Post-Game content.
7) Ditto for Reincarnation and Character Worlds.
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I think that covers the basic basics. So long as you keep the above in mind, have fun with Disgaea 4! ^_^