To enter the Item World in this installment, you must talk to the Thief standing parallel to Geoffrey.
The Item World works just as it does in previous installments, each floor completed (Either by clearing the stage in question or entering the Exit Portal) increases the Item's level by 1. Be aware that Normal Items have 30 floors, Rare Items have 60 floors, and Legendary Items have 100 floors, with an Item God or Item God 2 on the final floor. (Rank 40 Items only for Item God 2) Also of interest is the fact that the Mystery Gates from Disgaea 2 return, albeit with different rooms and features.
In this installment, players can perform another unique feature: Reverse Pirating.
Reverse Pirating is when the player raids Item as a Pirate, attempting to kidnap as many Innocents (Or Specialists to some) as they can.
Resistance can come in the form of Notorious Residents, Other Pirates, the Prism Rangers, and the Space Police. They appear in the same way that Pirates would appear if playing in a Normal Item World campaign, just as randomly.
Reverse Pirating is achieved by entering the Item World of an Item like usual. Once you choose which Item you wish to Pirate, you will be asked to choose a Pirate Ship to use. Each Pirate Ship has a certain amount of Innocents it can hold.
Once inside the Item World, the amount of Innocents that can be taken is determined by the Rarity of the Item (Rare and Legendary Items mean a higher Population amount, possibly meaning more Innocents that can be taken.) the Ship you choose, and your own power and patience.
Also, in order to enter the Land of Carnage in this installment, You must acquire Illegal Tickets from Pirates (Much in the way of Treasure Maps in Disgaea 2 and Dark Hero Days.) Once they are all received, You must talk to the X-Dimensional Guide and complete 25 X-Dimension stages, access being granted upon completion. No special characters can be recruited in the Land of Carnage in this installment, but there are Pirates that can only be fought here, as well as Rank 35 Items being available here.
Here is the Thief's official description of the Item World in Disgaea 3: The item world is an alternative world that exists inside an item. There are many residents in the item world and most are bad residents called Notorious so you can defeat them. But they can be very strong. Raise your level a good amount before you challenge them or they'll kill you. By the way, if you want to go into the item world of an equipment you have equipped, you need to take it off. Basically, you're entering the world of that item so you can't take it with you. Have extra equipment ready.
|Bribe Shop||Talk to Domgo a lot of times.||Able to purchase special items for bribing.||B1-99F|
|Corsica's Tower||-||Corsica sells Serums to improve your stats.||B1-99F|
|Guarded Treasure Room||-||Defeat Ifrit to get the Treasure Chests.||B1-99F|
|Illegal Room||Talk to Spiritus a lot of times.||Purchase Illegal Tickets. Inventory from B1-49F differs from B51-99F.||B1-99F|
|Item Fortune Teller||Talk to Zour a lot of times.||Fortune telling: Great (+5), Good (+3), Bad (-3), Worst (-5).||B1-99F|
|Item Shop||Talk to Chekitoutyo a lot of times.||Sells up to Rank 34 Items. (39 in LoC.)||B1-99F|
|Item World Carnivale||Talk to Mint a lot of times.||PA Microphone, Mana Potion, Bribe and Item Shops.||B1-99F|
|Item World Nurse's Room||Talk to the Alraune on the right a lot of times .||Item World Hospital.||B1-99F|
|Mana Potion Room||Talk to Shortie a lot of times.||Purchase Mana Potions.||B1-99F|
|Mr. Gency Exit Room||Talk to Misha a lot of times.||Talk to Misha for a free Mr. Gency Exit.||B1-99F|
|Music Room||Talk to Tenpay a lot of times.||Purchase BGMs you have heard at least once.||B1-99F|
|PA Microphone Shop||Talk to DJ Yuichi a lot of times.||Purchase PA Microphones.||B1-99F|
|Painting Room||Talk to Painta a lot of times.||Recolor a generic character.||B1-99F|
|Prinny's Inn||Talk to Piyokko a lot of times.||Pick one of the three Treasure Chests.||B1-99F|
|Rip Off Bar||Talk to the attendants a lot of times.||Pay HL to increase the Bonus Gauge.||B1-99F|
|Treasure Room||-||Rare and Legendary Treasure Chests.||B1-99F|
|Winding Road||Talk to Prin Roshi a lot of times.||Purchase EXP Potions.||B1-99F|
|Worker Room||Refuse the assassination request a lot of times.||Pay 50k HL to assassinate Gatekeepers for the next five floors.||B1-99F|
|Save Icon Shop||Talk to Pickles a lot of times.||Purchase Savegame Icons.||B1-99F|
|Monster Room||-||Defeat all enemies in two turns to add +3 levels to the Item.||B31-99F|
|Picture-Story Teller||Talk to Goldknuckle a lot of times.||Purchase recovery items.||B31-99F|
|Monster Training Room||Talk to Swami Kanda a lot of times.||Receive a free Magichange Weight.||B31-99F|
|Level Sphere Collector||Talk to Sphere King a lot of times.||Claim prizes for Collected Level Spheres.||B31-99F|
|Diez Gentlemen Room||-||Defeat all Diez Gentlemen within two turns to add +5 levels to the Item.||B31-99F|
|Axel's Room||Talk to Axel a lot of times.||You can talk to Axel.||B61-99F|
|Skill Transfer Room||Talk to Bandu a lot of times.||Transfer skills from one ally to another.||B61-99F|
|Trophy Shop ||-||Get the Trophy Shop Trophy (Bronze).||B91-99F|
- ↑ Added in a Disgaea Patch.